Community Interest Company: a Social Enterprise Organisation

Project Report

Health Needs Assessment: Stroke in South West and South East London

Author: Version: Date: Client: Ref No:

Dr John Hayward, Sarah Martin, Dr Michael Soljak Final Version 16.03.09 South West and South East London Cardiac and Stroke Network Boards P132

A Social Enterprise organisation and Community Interest Company Registered office: PO Box 1295, 20 Station Road, Gerrards Cross, Buckinghamshire, SL9 8EL English Company Number: 06480440 VAT Registration: 926 9466 78 www.phast.org.uk E&OE

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Public Health Action Support Team (PHAST) The Public Health Action Support Team (PHAST) is a Community Interest Company. This is a type of social enterprise that is committed to using its surpluses and assets for the public good. Social enterprises are social mission driven organisations which trade in goods or services for a social purpose.1 PHAST is based at Imperial College, London. It has over 60 experienced and expert public health professionals whose aim is to improve the health of the population and reduce inequalities. Many have worked at high level in the NHS, the Department of Health or in academia. Quality assurance and due diligence processes are in place to ensure all associates work to the highest standard. PHAST also has associates with economic, ethical and legal expertise. For further details see www.phast.org.uk Dr John Hayward Dr John Hayward was a GP in Bristol and in London for many years before retraining in public health. He was a consultant in public health medicine at Brent and Harrow Health Authority from 2000-2002, and Director of Public Health for Newham PCT 2002-2005. He co-chaired the groups developing NICE Guidelines on Tuberculosis in England & Wales and has a special interest in the health inequalities of children in care. He now works as an independent public health specialist and as a GP in North London. He is an associate consultant of PHAST, for whom (with Sarah Martin) he has published health needs assessments for stroke in North East London and in Redbridge. Sarah Martin Sarah Martin has worked within the health informatics arena for over 12 years. She first started out as an analyst in the pharmaceutical industry and then moved into the health informatics world of the NHS as an Information Exploitation Officer for the Department of Health - monitoring and developing the data quality of information flows throughout London-wide NHS Trusts. Sarah now works full time as a Senior Public Health Intelligence Analyst and also lends her information specialist services to PHAST as a PHAST Associate.

1

Whereas conventional businesses distribute their profit among shareholders, in social enterprises the surplus goes towards one or more social aims which the business has. PHAST will invest any surplus into development of new products and working with charities. In line with this PHAST directors and shareholders receive no dividends for their work in managing PHAST CIC. PHAST CIC is also regulated by the CIC Regulator, based at Companies House, to ensure it fulfils its Social Enterprise objectives with a mandatory requirement for annual audit.

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Dr Michael Soljak Dr Michael Soljak is a medical graduate who trained in paediatrics and then public health in the US and New Zealand. He holds postgraduate qualifications in these two specialties (Fellow of the Royal Australasian College of Physicians, Masters in Public Health, Fellow of the Australasian Faculty of Public Health Medicine, and Fellow of the UK Faculty of Public Health). He has worked in the UK for the last 15 years, as an Executive Director of Public Health in a large NHS commissioning organisation West London, and since 2004 for the UK Department of Health developing public health information and intelligence capacity. He is also Hon. Senior Lecturer and Postgraduate Researcher at Imperial College, London, and a member of the Public Health & Statistics Reference Group of the Information Standards Board. Acknowledgment We are indebted to David Murray, Consultant in Public Health and PHAST Operational Director, for quality assurance and advice.

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TABLE OF CONTENTS
1. EXECUTIVE SUMMARY............................................................................6 1.1 Background ......................................................................................6 1.2 Epidemiology Review ........................................................................6 1.3 Hospital Activity ................................................................................8 1.4 Stroke Prevalence and Prevention ......................................................8 1.5 Commissioning ............................................................................... 10 1.6 Recommendations .......................................................................... 10 2. INTRODUCTION................................................................................... 12 2.1 Origin of this work .......................................................................... 12 2.2 Objectives, boundaries and limits to this work .................................. 13 2.3 Structure of this report .................................................................... 14 2.4 Understanding current context......................................................... 14 3. EPIDEMIOLOGY REVIEW ...................................................................... 15 3.1 Population demography................................................................... 15 3.1.1 What this section contains......................................................... 15 3.1.2 Location ................................................................................... 15 3.1.3 Deprivation, life expectancy and demography............................. 16 3.1.4 What this section shows............................................................ 21 3.2 Mortality......................................................................................... 22 3.2.1 What this section contains......................................................... 22 3.2.2 Limitations of information.......................................................... 22 3.2.3 Causes of death categorised as due to stroke ............................. 23 3.2.4 Understanding death rates ........................................................ 24 3.2.5 Trends in stroke death rates over the last 14 years..................... 24 3.2.6 Trends summary at sector level ................................................. 27 3.2.7 Mortality trends by PCT ............................................................. 28 3.2.8 Stroke mortality rates in comparison to other London PCTs ......... 31 3.2.9 Numbers of deaths from stroke ................................................. 35 3.2.10 The effect of population age profiles ........................................ 37 3.2.11 Numbers of stroke deaths by diagnostic category and age......... 39 3.2.12 Deaths and gender ................................................................. 42 3.2.13 Excess deaths in SE London..................................................... 44 3.3 Understanding numbers and rates ................................................... 45 3.3.1 Numbers of deaths ................................................................... 45 3.3.2 Rates ....................................................................................... 46 3.3.3 What this chapter shows ........................................................... 46 4. HOSPITAL ACTIVITY ............................................................................ 49 4.1 What this chapter contains ........................................................... 49 4.2 Numbers of hospital admissions for stroke .................................... 49 4.3 Hospital admission rates .............................................................. 52 4.4 Admission rate trends .................................................................. 53 4.5 Hospital admissions for transient ischaemic attack ......................... 54 4.6 Length of stay (LOS) in hospital after acute stroke......................... 56 4.7 Financial issues related to hospital activity .................................... 59
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4.8 What this section shows............................................................... 60 5. STROKE PREVENTION AND PREVALENCE .............................................. 62 5.1 Introduction ................................................................................ 62 5.2 Risk factors for stroke .................................................................. 62 5.3 Secondary prevention of stroke .................................................... 63 5.4 Primary prevention of stroke ........................................................ 64 5.5 Stroke Prevalence........................................................................ 67 5.6 Quantifying likely stroke prevalence .............................................. 67 5.7 Methods...................................................................................... 68 5.8 What we found............................................................................ 68 5.9 Modelled stroke prevalence and prevalence in GP stroke registers .. 69 5.10 Quantifying the impact of risk factors on stroke prevalence .......... 71 5.11 Atrial Fibrillation......................................................................... 73 5.12 Attributing future stroke prevalence to individual risk factors ........ 74 5.13 Predicting the impact of risk factor reduction on stroke prevalence75 5.14 Comment on time lags ............................................................... 77 5.15 Stroke Prevention through management of high blood pressure ... 77 5.16 How to assemble coherent stroke prevention programmes across SW and SE London ............................................................................ 79 5.17 National guidance and initiatives................................................. 80 5.18 Vascular Risk Assessment; Department of Health’s approach........ 82 5.19 Stroke Prevention in London – the role of Healthcare for London .. 83 5.20 The Case for Preventing Stroke in London ................................... 83 5.21 Treatment of hypertension and atrial fibrillation in older people .... 84 5.22 Preventing stroke in older people (over 75 years) – a local case study for this report........................................................................... 84 5.22 Summary – what this chapter shows........................................... 86 6. COMMISSIONING................................................................................. 88 6.1 Epidemiology background ............................................................ 88 6.2 Stroke Prevention ........................................................................ 88 7. DISCUSSION........................................................................................ 90 7.1 Demography ............................................................................... 90 7.2 Ethnicity...................................................................................... 90 7.3 Death rates ................................................................................. 91 7.4 Addressing inequalities................................................................. 92 7.5 Numbers of deaths ...................................................................... 92 7.6 Hospital activity ........................................................................... 93 7.7 Predicting future patterns of need and demand ............................. 94 7.8 Stroke Prevention ........................................................................ 95 7.9 Commissioning Plans ................................................................... 95 8. RECOMMENDATIONS ........................................................................... 97 Annex: Stroke Prevalence Preventions Scenarios, South London PCTs / Sectors.................................................................................................... 99

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1. EXECUTIVE SUMMARY
1.1 Background
This work was commissioned from PHAST by the Director, South West and South East London Cardiac and Stroke Network Boards as a pragmatic needs assessment, to help the networks understand local stroke priorities and to support the commissioning of stroke services within both sectors. Stroke has been highlighted as a priority for change in the NHS Next Stage Review2, and the National Stroke Strategy3 has set a comprehensive agenda with quality markers to be met over time across the whole patient care pathway, from acute onset of a stroke up to the end of community based rehabilitation. This needs assessment was undertaken in parallel with a process by which Healthcare for London proposes to designate 8 hyperacute stroke centres and about 25 stroke /TIA units across London, with the aim of overhauling and modernising the system by which acute stroke is managed across the capital.4

1.2 Epidemiology Review
Demography
Deprivation is highest in inner city northern localities in both SW and SE London; life expectancy is worse here, both for men and for women. Deprivation is generally greater in SE London compared with SW London. People from Black and Minority Ethnic (BME) groups tend to live in the inner city areas. People over 65 years of age predominantly live in less deprived areas.

Death rates from stroke – trends over time
Stroke death rates are falling across both SW and SE London, but the relative position of the two sectors is different. In SW London, over the last 14 years as the London average rate has fallen, SW London rates have stayed very close to the London rate. In SE London, stroke death rates have been consistently higher than the London rate and have recently been falling rather more slowly than the London and national rates.
2 3 4

High Quality Care for All: NHS Next Stage Review Final Report. London: Stationery Office Cm 7432, June 2008. National Stroke Strategy. London: Department of Health, 2007. Stroke Strategy for London. London: Healthcare for London, November 2008
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Stroke death rates in South London PCTs
Death rates from stroke in South London are highest in the SE London inner city PCTs: Lambeth, Lewisham and Greenwich, all of which have rates significantly higher than the London average. Death rates from stroke in Bromley are much lower than the London average. In SW London, by contrast, death rates are around the London average in all PCTs except Richmond & Twickenham, which has significantly low rates. Death rates from stroke in people under 75 years are highest in Lambeth (highest in London), Lewisham, Greenwich and Southwark. Death rates under 75 years in all other SW and SE London PCTs are around the London average or significantly lower than that average (Richmond & Twickenham, Bromley (3rd and 2nd lowest in London respectively).

Numbers of stroke deaths
The pattern of death numbers is different. The greatest numbers of stroke deaths occur in PCTs with average or low death rates. The greatest number of stroke deaths in any one London PCT is found in Sutton & Merton, closely followed by Bromley (2nd highest) and Croydon (3rd highest). Bromley has the second lowest stroke death rate in London, but the second highest number of stroke deaths. The reason for this pattern is a combination of larger population size and older age profile in the more peripheral London boroughs. When the number of deaths considered is restricted to people under 75 years, by far the greatest number occurs to residents of Sutton & Merton (SW London) and Lambeth (SE London), with Croydon and Lewisham not far behind. Where people under 75 years are considered, the boroughs with the highest numbers are more likely to be those with the high death rates, because the effects of large numbers of deaths in older people have been excluded.

Stroke deaths and age
Age is an important determinant of stroke risk. In SW London in 2007, 79% of stroke deaths were in people over 75 years of age. In SE London the proportion was 78% (similar to our findings in NE and NC London). In boroughs with high deprivation and especially high death rates in people under 75 years (e.g. Lambeth), there were still more stroke deaths in people over 75 years compared with those aged less than 75 years (Lambeth 83:25). So even in boroughs with lower numbers of deaths, lower life expectancy and higher death rates in younger people, the vast majority of stroke deaths are still in people over the age of 75 years. This has very important implications for local stroke prevention programmes (see later below).
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Stroke deaths and gender
Stroke death rates are generally higher in men than women across all ages. Numbers of stroke deaths, however, are higher in women than in men, because women live longer and more women than men are exposed to stroke risk in later life.

Excess stroke deaths in SE London
We have calculated that in SE London, the number of deaths that would need to be prevented in one year for the sector to have the same death rate as London is 63: 31 female and 32 male. Only 15 of the 63 deaths (24%) would be in people under 75 years of age. These findings reinforce the need for stroke prevention initiatives to include work with people over 75 years.

1.3 Hospital Activity
In both SW and SE London, the highest totals of acute hospital admissions for stroke were from residents of boroughs outside the inner city, reflecting the geographical pattern whereby most people over 65 years old live in outer London locations. Most destination hospitals to which patients are admitted are local to where they live, though in SW London there is more of a trend for admissions to more distant teaching hospitals. Hospital admission rates are average or low across the whole of South London, with the exception of Kingston, where admission rates are significantly higher than the London average. Admission rates for TIA are also generally low across South London (with the exception of Lewisham), suggesting perhaps a high admission threshold. This may change with the Healthcare for London proposals.3 Average length of stay (LOS) for a stroke admission in SW London is lower than the London average, having fallen recently to less than 20 days (London average: 21 days). Average LOS is a little higher in SE London (22 days). Programme budget data suggest that spend on disorders of cardiac rhythm should perhaps be greater in SW London (although London spends poorly on this topic as a whole).

1.4 Stroke Prevalence and Prevention
Stroke can often be prevented through control of blood pressure, atrial fibrillation, smoking and other recognised risk factors. We have applied
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information on the known prevalence of these factors to develop a model of future stroke prevalence in SW and SE London, under different prevention scenarios. In most PCTs in SW and SE London, stroke prevalence is set to increase markedly between now and 2020. Our model shows that this increase will be offset if smoking and hypertension prevalence can be reduced. Hypertension and smoking together account for more than half of the attributable risk for stroke. GP information systems across South London under-record stroke prevalence by up to 30%. Quality and Outcomes Framework (QOF) prevalence is a poor predictor of service need and should not be used as a baseline for assessing the impact of GP stroke prevention measures. There is a case for advocating case finding (for hypertension and atrial fibrillation) at general practice level. Current national stroke prevention initiatives, to be rolled out by PCTs from April 2009, are targeting people between the ages of 40 and 74 years.5 It is important that local programmes should include case finding for hypertension and atrial fibrillation within this age group, as well as work to reduce smoking prevalence and obesity. Early diagnosis and treatment of hypertension in Black African and AfricanCaribbean men is especially important and a priority in parts of South London where there are large BME communities, many of whom live in deprived and disadvantaged localities. People of South Asian origin are at increased risk of diabetes and cardiovascular disease in general, and many men from BME groups are smokers. All these factors increase stroke risk across all age groups. The national stroke prevention initiatives appear to have failed to grasp that nearly 80% of stroke deaths occur in people over the age of 75 years, who are outside the age limit for the Vascular Checks programme but in whom stroke can still be prevented by tackling specific risk factors. The key point is that so many stroke events and stroke deaths occur in people over 75 years, that unless some prevention work targets older people, stroke incidence will not fall very much for several years yet – until the population currently in their forties, fifties and sixties benefits in future years from stroke risk reduction initiatives happening now. Three snapshot studies in South London suggest that general practice teams could quite easily screen their population of patients over 75 years of age for hypertension and atrial fibrillation. An initiative to screen older people in
5

Putting Prevention First. Vascular checks: risk assessment and management. London,
Department of Health, April 2008.

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general practice (for example, linked to flu vaccination) is feasible, relatively inexpensive and would prevent more strokes in the next few years than solely screening people between the age of 40 and 74 years. It is essential to do both.

1.5 Commissioning
At the request of the two Cardiac and Stroke Network Boards, we have reviewed the Collaborative Commissioning Intentions (CCI) for Stroke (2008) for both SW and SE London. Both documents contain some public health data as background and use prevalence figures which (in our estimation) underestimate stroke prevalence significantly. We recommend that a standard dataset be used for future commissioning guidance, based on that used in this report. Both CCI documents advise PCTs on stroke prevention, and refer to the national vascular checks programme to be rolled out by all PCTs from April 2009. However, neither has captured the age related issues for stroke prevention - that it is important to prevent strokes in older people as well as in those aged 40 – 74 years in hard to reach and deprived communities. The SW London CCI advice suggests that prevention initiatives should include smoking cessation, obesity services and exercise programmes. Obesity reduction and exercise are important for long-term risk reduction, but we believe that clinical interventions to control hypertension and atrial fibrillation are likely to have greater and more immediate impact on numbers of stroke events. Smoking cessation is also important.

1.6 Recommendations
1. The SW and SE London Cardiac and Stroke Network Boards should continue to monitor stroke death rates and death numbers across all PCTs in each sector, using robust and standard sources of public health information. A wide variation in hospital admission rates for stroke has been observed across PCTs in both SW and SE London. The reasons for this are unclear, but it is possible that some low rates could be partly due to high admission thresholds. Events involving local clinicians (to explore care pathways and referral problems) would probably be helpful in all PCTs but especially those with low rates, such as Croydon, Richmond & Twickenham (SW), Bromley and Bexley (SE).

2.

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3. 4.

Low rates of admission for TIA are very striking across both sectors (except in Lewisham) and should similarly be investigated. Both Boards should advocate stroke prevention initiatives for people under the age of 75 years, in line with the national Vascular Risk Assessment (VRA) Programme. This should be implemented by all PCTs, but especially those with particularly high death rates and numbers in this age group – Lambeth, Lewisham and Greenwich (SE). This work should involve targeted initiatives in areas of deprivation, black and minority ethnic communities and groups that may be hard to reach. Stroke prevention programmes should also include specific interventions to reduce stroke risk in the age group in which most stroke events occur – those over the age of 75 years. This is a priority for all PCTs in both sectors, but especially for those with particularly high burdens of stroke illness: Sutton & Merton and Croydon (SW), Bromley and Bexley (SE). All stroke prevention programmes should emphasise the impact of diagnosis and effective management of hypertension and atrial fibrillation across all age groups, and of smoking cessation (as well as other stroke risk factors such as abnormal lipid profiles and obesity). Case finding for hypertension and atrial fibrillation is a particular priority. Both Network Boards should consider commissioning work to model in detail the future demand for hospital admissions for stroke between now and 2020, assuming clinical care pathways are optimised, and taking into account future stroke prevalence under different prevention scenarios. This need to model future demand for stroke services should be raised by both Boards in discussion with Healthcare for London – to ensure that the modelling is robust, transparent and able to inform capacity planning for South London. Future commissioning guidance for PCTs across both sectors should draw on robust public health information. It should contain detailed advice on stroke prevention, incorporating not only the VRA programme, but also the need to screen people over 75 years of age for risk factors such as hypertension and atrial fibrillation – perhaps through the use of Local Enhanced Service contracts with general practice teams.

5.

6.

7.

8.

9.

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2. INTRODUCTION
2.1 Origin of this work
This work was commissioned from PHAST by the Director, South West and South East London Cardiac and Stroke Network Boards as a pragmatic needs assessment, to help the Network to understand local stroke priorities and to support PCTs in the commissioning of local services for people suffering stroke in South London. It is currently a national priority for the NHS to improve the quality of services for people experiencing a stroke in England and Wales. Stroke is one area highlighted in the NHS Next Stage Review6 as a priority for change, introducing the concept of specialist centres for acute stroke care. Not only should this lead to better outcomes for those suffering a stroke, but there is also the opportunity more effectively to prevent strokes from occurring. The National Stroke Strategy,7 published in 2007, has already set a comprehensive agenda with a series of national quality markers to be met over time. The national agenda is complemented in London by a complex process to determine the designation of acute stroke care centres, running in parallel with the work to produce this report. Meanwhile there has been the additional need for cardiac and stroke network boards across London to understand the epidemiological picture of stroke deaths and prevalence within the populations in their sectors, the patterns of hospital admissions and the opportunities to prevent strokes and transient ischaemic attacks. This report builds on earlier work undertaken by PHAST to assess stroke health needs in the North East London sector, and (within NE London) within the London Borough of Redbridge.8,9 It will be followed in March 2009 with similar work across North Central London.

6

7 8

9

High Quality Care for All: NHS Next Stage Review Final Report. London: Stationery Office Cm 7432, June 2008. National Stroke Strategy. London: Department of Health, 2007. Hayward JA, Martin S. Health Needs Assessment: Stroke in North East London. London: PHAST, June 2008. Hayward JA, Martin S. Health Needs Assessment: Stroke in Redbridge. London: PHAST, November 2008.
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2.2 Objectives, boundaries and limits to this work
The Objectives of this needs assessment are shown below. South West and South East London Stroke Health Needs Assessment Project Aim To perform a systematic review of incidence, prevalence and impact of Stroke and Transient Ischaemic Attack (TIA) within SE and SW London, with comparison made between the sectors and both London and England as a whole. Project Approach and Objectives The report will primarily focus on public health issues and will include: • • • • Epidemiological review of stroke prevalence and of outcomes across SE and SW London (including a broad review of information captured in general practice). Review of local hospital activity across SEL and SWL compared to London and England. Review of potential benefits within the sector from prevention work to decrease risk of stroke. Improved understanding and where possible prediction of the impact of demographic changes across South London on demand / activity and service provision. Review of commissioning and investment plans into stroke services (including any recent investment decisions) and advise whether resources are being targeted appropriately. (The joint commissioning arrangements for both SEL and SWL PCTs will need to be considered). Comparison between inequalities identified in the report and current investment plans. Recommendations grouped in order of impact and cost effectiveness to support prioritisation of work / initiatives as result of the review, and taking in to account recent national policy documents and drivers for change.

•

• •

Out of scope
• This review will not cover a review of disability at an individual or population level, either as an indicator in relation to severity of stroke, or to establish requirements for ongoing care. This review will not cover a review of individual PCT stroke services. These objectives have a public health focus, and do not include a review of services. In particular, this work intentionally does not review acute and hyperacute stroke services for South London, since there is already a process underway for designating hyperacute and acute stroke units (see Context below). The objectives also include stroke prevention but not stroke rehabilitation, since the latter is to be the subject of a separate study.

•

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2.3 Structure of this report
This report is divided into discrete chapters, each related to different sources of information and evidence. This chapter outlines the report’s objectives and structure. Chapter 2 reviews stroke epidemiology across South West and South East London, describing population demography, life expectancy and mortality from stroke. Chapter 3 describes hospital activity, including admission patterns, rates and trends. Chapter 4 describes stroke prevalence and stroke prevention. Chapter 5 discusses commissioning issues. The content and purpose of each section is explained at the outset and a brief summary of the findings placed at the end. However, many of the issues overlap. There is therefore a Discussion chapter to pull these together and achieve a synthesis of interpretation and recommendations for action within SW and SE London.

2.4 Understanding current context
This needs assessment was undertaken between November and December 2008, with the final report agreed in March 2009. During 2008, Healthcare for London had developed a Stroke Strategy for London10 (outlining London’s response to the National Stroke Strategy and A Framework for Action11 as part of Lord Ara Darzi’s vision for health services across the capital. The Stroke Strategy for London, published in November 2008 while this work was in progress, describes in detail the process for designating hyperacute stroke units and stroke units across the capital. This process has been running in parallel with this needs assessment. The Stroke Strategy for London includes appendixes on two further topics of importance: stroke prevention and stroke rehabilitation. This health needs assessment includes a section on stroke prevention (together with the results of a prevalence study) and is designed to complement the guidance on stroke prevention within Healthcare for London’s stroke strategy.

10

Stroke Strategy for London. London: Healthcare for London, November
2008.

11

A Framework for Action. London: Healthcare for London, July 2007.
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3. EPIDEMIOLOGY REVIEW
3.1 Population demography
3.1.1 What this section contains

This section describes the geography and basic demography of SW and SE London, with its constituent boroughs and PCTs. Understanding this demography is important. Stroke is known to be more common in deprived communities and in people of black and minority ethnic origin, so we would expect rates of stroke incidence and of stroke deaths to be highest in those localities that are most deprived and where most ethnic minority communities live. Stroke is also more common as people grow older. So it is also important to know the geographical locations in which older people live. These three main factors – deprivation, ethnic origin and old age (all of which influence individual lifestyle or stroke risk) - are likely together to determine current and future patterns of need and demand for stroke care. We have therefore prepared maps to show the geographical distribution of deprivation factors, life expectancy, populations of people over 65 years of age and of people from black and minority ethnic groups. These distributions will be seen to differ in important ways.

3.1.2 Location

South London is divided into two sectors: South West (SW) and South East (SE) London. Together these sectors comprise all London boroughs lying south of the Thames, with a total population of 2,907,635 (SW=1,621,510 and SE=1,286,125). SW London contains five PCTs: Wandsworth, Richmond & Twickenham, Kingston, Sutton & Merton and Croydon. Each PCT is co-terminous with one London borough with the exception of

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Sutton & Merton PCT, which covers the boundaries of two boroughs. SE London contains six PCTs: Lambeth, Southwark, Lewisham, Greenwich, Bexley and Bromley. All are co-terminous with a London borough bearing the same name. The geography of SE and SW London is shown in Map 1, which also shows the location of the principal hospitals in the two sectors.

Map 1

PCTs in SW (blue) and SE London (pink) + principal hospitals

3.1.3 Deprivation, life expectancy and demography

There is substantial deprivation in parts of each sector. There are also areas of considerable affluence, sometimes in localities adjacent to those with poverty in the same borough. This has led to complex patterns of health inequality within and between most boroughs, and what can be a confusing pattern of healthcare need across South London.

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Map 2 shows the distribution of deprivation across SW and SE London. It can be seen that by and large most deprivation is to be found towards the north of the two sectors, although there are patches of deprivation in all South London boroughs. There is a large area of deprivation in the north east of Bromley. Map 2 Indices of Deprivation 2007 at Lower Layer Super Output Area (LSOA), SW and SE London

Source: Department of Communities and Local Government, Indices of Deprivation 2007.

Deprivation and life expectancy are linked. Socio-economic factors are known to be powerful determinants of health and life expectancy tends to be shorter in areas of deprivation and relative poverty. Map 3 and Map 4 show the distribution of male and female life expectancy across SW and SE London. The localities with longest life expectancy tend to be different from those with the greatest deprivation – the two factors appear to be inversely related.
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Map 3

Male life expectancy 2002-06 by ward, SW and SE London

Map 4 and SE

Female life expectancy 2002-06 by ward, SW London

Source: London Health Observatory.

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The longest life expectancy in South West London is to be seen in Richmond (males=78.5 years and females=82.5 years), and the shortest in Wandsworth (males=76.2 years and females=80.6). In South East London the longest life expectancy is to be seen in Bromley for both males and females (males=78.5 years and females=82.5 years), and the shortest in Lambeth for males (74.7 years) and Lewisham in females (79.7 years). Broadly speaking, longer life expectancy is to be seen away from the inner city boroughs with the worst deprivation.

Map 5 shows the geographical distribution of people living over the age of 65 years of age in SW and SE London.

Map 5

Proportion of people living over 65 yrs (%), by Ward, SW and SE London

Source:

Office for National Statistics, ONS

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Most people living over the age of 65 years live in the outer boroughs, and in the outer neighbourhoods of these outer boroughs. By contrast people in communities of black and minority ethnic (BME) groups12 tend to live nearer the centre of London. Map 6 shows the distribution of people from BME groups. The pattern is strikingly different – BME groups in general and most of those over 65 live in different parts of South London. The distribution of BME groups overlaps quite closely with the distribution of deprivation factors.

Map 6

Proportion of BME groups (%), by Super Output Area, SW and SE London

Source:

Office for National Statistics, ONS

12

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3.1.4 What this section shows These maps show that deprivation is worse in the northern localities in both SW and SE London, where life expectancy is also worse, both for men and for women. People over 65 years predominantly live away from the more deprived parts of South London, whereas people from BME groups tend to live in the inner city localities. There are some exceptions to this pattern. For example, there is large area of profound deprivation away from the inner city, in the north east of Bromley, where life expectancy is lower than elsewhere in that borough, but where there are many people living over the age of 65 years. Few people living in this part of Bromley are from BME groups. The next section shows how the patterns of death rates and death numbers are fundamentally different across both sectors. The localities with high rates and those with high numbers are not necessarily the same; the maps above help to explain these differences, as will be discussed in some detail.

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3.2 Mortality
3.2.1 What this section contains This section presents information on deaths from stroke across SW and SE London. This includes trends in death rates over the last 14 years for which information is available, both across the two sectors as a whole and attributed separately to the PCTs within them, all compared with London as a whole and England. We also present rates and numbers of stroke deaths in each PCT within the two sectors, averaged over the last three years, in comparison with all London PCTs, and both London and national figures. We analyse rates and numbers of deaths by gender and by age. We show how deaths are categorized, with the relative burden of stroke deaths due to thrombosis / infarction compared with those due to haemorrhage or other causes. Lastly, we show the extent to which stroke deaths exceed the total we would expect if local rates were the same as the rest of London, and we calculate the number that would need to be prevented in an average year for the sectors to achieve the same death rates as the capital as a whole. 3.2.2 Limitations of information It is important to remember that the accuracy of any information is only as good as the accuracy of its source. In the case of mortality data, much of the information is dependent on the accuracy and completeness of death certification.13 In a later chapter we will be considering hospital activity, including admissions. This information is dependent on the completeness and accuracy with which a
13

The format of the medical certificate of cause of death was laid down in 1927, and forms the basis for subsequent international recommendations up to the present time. The certifying doctor is required to enter the conditions which led directly to death in part I of the certificate, so that the disease or condition which started the sequence is in the lowest used line. Any other significant conditions which may have contributed to the death are put in part II. The cause section of coroners' certificates has had the same basic format since 1993, although other details are different. These certificates are used to code the cause of death to codes from the International Classification of Diseases. (http://www.ons.gov.uk/aboutstatistics/classifications/international/icd-10/death-reg/index.html)

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hospital admission spell is coded by the hospital concerned. This function has improved in all hospitals, but there remains a degree of variability. As is usually the case, the information we have is far from perfect, but is the best that can be obtained from current data sources. It is best to assume (especially where the numbers involved are reasonably large) that the extent of any data inaccuracies or misclassifications is much the same in all boroughs and across London and England in general. 3.2.3 Causes of death categorised as due to stroke ONS death data use a set of specific internationally agreed codes to define what is a death due to stroke. These ICD-10 codes14 are shown in the box below. It can be seen that deaths described as due to stroke include deaths due to subarachnoid haemorrhage15 and other cerebral haemorrhages, together with other causes of death from cerebrovascular disease. These mortality trends, therefore, use quite a wide definition of what comprises a death due to stroke. Data used in other reports or sources may use more restricted range of ICD-10 codes, so it is important to ensure likewith-like comparisons. Box 1. ICD-10 codes for causes of death classified as due to stroke I I I I I 60: 61: 62: 63: 64: Subarachnoid haemorrhage Intracerebral haemorrhage Other non-traumatic intracranial haemorrhage Cerebral infarction16 Stroke, not specified as haemorrhage or infarction Occlusion/stenosis precerebral arteries not resulting in cerebral infarct Occlusion/stenosis cerebral arteries not resulting in cerebral infarct Other cerebrovascular diseases Cerebrovascular disorders in diseases classified elsewhere Sequelae of cerebrovascular disease
International Classification of Diseases – 10. The latest version of the international classification of diseases. Subarachnoid haemorrhage – a haemorrhage usually due to rupture of a congenital aneurysm sited in one of the main blood vessels just beneath the brain. Can be triggered by hypertension, but often occurs spontaneously with minimal warning and therefore may not be preventable. Version: Final Page 23 of 106 16/03/09

I 65: I I I I
14

66: 67: 68: 69:

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3.2.4 Understanding death rates Death rates show deaths as a proportion, typically expressed as a number of deaths per 100,000 head of population per year. We have used rates that are standardised for age and sex,17 and therefore take into account differences in age and sex profile of the populations studied, compared with, say, London and England as a whole. Differences in standardised rates observed between different populations are therefore due to factors other than age or gender. The strength of using age and sex-standardised death rates is that it is then easy to make comparisons between the risk of death in one population compared with another, excluding any differences in population size or in age and gender profile. We can therefore make valid comparisons between and across sectors or PCTs, and with national and regional comparators. The other strength of considering rates is that it may be possible to identify important inequalities of death risk in different communities. These are health inequalities, and on grounds of equity and fairness efforts should be made to reduce them. Reducing health inequalities has been mainstream health policy since the Acheson Report in 1998.18 Although high death rates may show need for better health and health care, death rates alone cannot predict levels of demand for care. Indeed the highest levels of demand for care may be found in localities with low death rates – an issue which is often misunderstood. This is explored later in this section (see page 35). 3.2.5 Trends in stroke death rates over the last 14 years These trends are drawn from data compiled by ONS from the principal causes of death described in death certificates lodged with the Registrar General. The information is drawn from the

16

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If the brain’s blood supply is interrupted, either by the formation of a clot within a cerebral artery (thrombosis) or by the lodging in an artery of a clot from elsewhere (embolism), brain tissue may die irreversibly. This is called cerebral infarction. Standardising for age and sex involves adjusting the observed rate to allow for differences in the age and gender profile of the population of interest in comparison with that of a standard reference population– in this case ONS uses that of England as a whole. Independent Inquiry into Inequalities in Health. (Chairman: Sir Donald Acheson). HMSO, November 1998. Version: Final Page 24 of 106 16/03/09

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Compendium of Clinical and Health Indicators.19 Deaths are ascribed to the borough of residence of the deceased, irrespective of where death occurred.

Stroke mortality trends across SW and SE London
Figure 1 shows the standardised mortality trend for stroke in people of all ages in SW and SE London, London and England between 1993 and 2006. The three-year rolling average is shown, in order to reduce random fluctuations between individual years. Figure 1 Standardised mortality rate from stroke - SW, SE London, London and England, 1993 – 2006
Source: Compendium14

All the mortality rates can be seen to be falling steadily across the 14 years shown. The national death rate for stroke fell by about 40% during this period. London’s death rate from stroke has been consistently lower than the national rate, probably reflecting the relative affluence of the capital despite the poverty and deprivation seen in some boroughs. The London death rate is not falling quite
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Compendium of Clinical and Health Indicators. Lakhani A, Olearnik H, Eayres D (eds). Clinical and Health Outcomes Knowledge Base. London: The Information Centre for health and social care / National Centre for Health Outcomes Development, 2008 Version: Final Page 25 of 106 16/03/09

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as rapidly as the national rate and the gap between them has narrowed appreciably. The death rates from stroke in both SW and SE London have also continued to fall. However the death rate in SE London has been consistently higher than those of both SW London and London as a whole, at times approaching or even exceeding (2004 and 2005) the national rate. The gap between the rates of the two sectors has been increased over the period covered.

Figure 2 shows the standardised mortality trend for stroke in people under the age of 75 years. Both the national and London trends show a steady decline in death rates; unlike the trend for all ages, London’s death rates in the under 75s have tended to be higher than the national rates and have remained higher since 1998. Figure 2 Standardised mortality rate from stroke <75 yrs. SW, SE London, London and England 1993 – 2006
Source: Compendium

The SW and SE London death rates also show a parallel reduction over the years. SW London’s rates have tended to remain below the London and national rates, while the rates in SE London have been noticeably higher than all the national, London and SW London rates.
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All these rates are adjusted for age and sex (so any differences are unrelated to age or gender profiles), but they are not adjusted for other factors such as deprivation or ethnicity. 3.2.6 Trends summary at sector level In summary, death rates from stroke in SE and SW London have been steadily falling over the years, as they have been nationally and in the capital as a whole. Across all ages, London has had lower death rates than England; SW London has had death rates usually comparable to the London rate, and SE London has had death rates higher than the London rate, but lower than the national rate. In the under 75s, rates everywhere are continuing to come down, but the relative positions are different. London has death rates slightly higher than the national rate. SW London has rates lower than the London rate, while SE London has had much higher death rates: higher than both the London and the national rates. The higher death rates generally in SE London are likely to be related to greater poverty and deprivation in those communities nearest to the centre of the city. They are also likely to be related to ethnicity, given that some ethnic groups (with a high density in central SE London, see Map 5) have an increased risk of cardiovascular disease. This is explored further later.

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3.2.7 Mortality trends by PCT

Mortality across all ages – PCT level
Figures 3 and 4 show the trends in mortality rates across all ages in the PCTs in SW and SE London respectively.

Figure 3

Standardised mortality rate trend, stroke all ages, SW London PCTs, London and England, 1993-2006
Source: Compendium

In SW London, the rates in all PCTs are generally falling in line with the national and London trends. Although the relative position of each PCT varies from year to year, Richmond & Twickenham has usually had death rates that are the lowest in the sector.

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Figure 4

Standardised mortality rate trend, stroke all ages, SE London PCTs, London and England, 1993-2006
Source: Compendium

In SE London, the rates of all PCTs, while falling, have tended to be higher than in SW London. Bromley has usually had the lowest rates and Greenwich, Lambeth and Lewisham the highest. There has been a noticeable increase in death rates from stroke in Lambeth in the last few years, to the highest value in the sector.

Mortality trends in under 75s – PCT level
Figures 5 and 6 show the trend in mortality rates in people under 75 years across the same PCTs.

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Figure 5

Standardised mortality rate, stroke <75 yrs, SW London PCTs, London and England, 19932006
Source: Compendium

Figure 6

Standardised mortality rate, stroke <75 yrs, SE London PCTs, London and England 1993-2006
Source: Compendium

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In SW London, the death rates are comparable across the sector’s PCTs, although Wandsworth has tended to have death rates slightly higher than the London average, while the remaining PCTs’ rates have been close to or below the London average. Richmond & Twickenham has had the lowest death rates in this age group across SW London. In SE London the pattern is rather different. In the under 75s, Lambeth, Lewisham, Greenwich and Southwark have had death rates that have been consistently higher than the London average. The rates in Bromley and Bexley by contrast have been consistently lower than the London and national average. 3.2.8 Stroke mortality rates in comparison to other London PCTs The bar chart in Figure 7 shows the death rates due to stroke for people of all ages across London PCTs, averaged across the last three years for which information is available (2004-06). The rates of all PCTs can be compared, each bar representing the rate in one PCT. The rates are (as before) directly standardised for age and sex to take account of the different age and sex distributions within the various PCTs. SW London PCTs are shown in blue, SE London PCTs are shown in pink, London in black and England in red. Figure 7 Standardised stroke mortality rates, all ages, London PCTs, London and England 2004-06
Source: Compendium

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How meaningful are differences between the rates of PCTs?
The exact value of any rate can differ from its neighbour’s simply play of chance. We can be 95% certain that the true value for each of these rates lies within the limits shown by the symbol extending across the top of each bar. When these 95% confidence intervals across different bars overlap, differences between PCTs may not be significant. When PCTs’ values are so different that the confidence limits do not overlap, then the differences are statistically significant, and may actually be very important.

I

What Figure 7 shows
The rates in SW London PCTs have similar or lower values, compared with London as a whole. Richmond & Twickenham has death rates amongst the lowest in the capital, while the PCT with the highest rate in the sector (Kingston) is near the mid-point of the distribution of values for London PCTs. By contrast, the rates in four of the six PCTs in SE London are amongst the highest in the capital. Lambeth, Lewisham and Greenwich are ranked first, third and fifth highest respectively. Bexley is ranked ninth. Southwark and Bromley have relatively low rates. Bromley’s rate (6th lowest) is significantly lower than the London average and is very similar to that of Richmond & Twickenham in SW London. The death rates across all ages can be studied in males and females separately (not shown). The pattern remains basically the same as for all persons taken together – Lambeth, Greenwich and Lewisham have some of the highest rates in London for both male and female deaths; Richmond & Twickenham and Bromley some of the lowest.

Stroke mortality rates in people under 75 years
Figure 8 shows standardised death rates from stroke in people under the age of 75 years in all London PCTs.

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Figure 8

Standardised stroke mortality rates, <75 yrs, London PCTs, London and England, 2004-06
Source: Compendium

In SW London, Wandsworth has the highest rate, but it is around the average for London. Croydon and Richmond & Twickenham have low rates; Richmond & Twickenham has the third lowest rate in the capital, almost identical to that of Bromley in the South East, and significantly lower than the London and national rate. Sutton & Merton and Kingston both have low rates. The pattern is again quite different in SE London, with four of the six PCTs having very high rates in comparison with other PCTs in London. Lambeth has the highest death rate in under 75s in the capital, with Lewisham lying fifth highest, Greenwich seventh and Southwark ninth. By contrast, Bexley has a low rate, and Bromley has the second lowest rate in London. Death rates in males and females under 75 years (not shown) show a very similar pattern to death rates in all people.

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Stroke mortality rates in people under 65 years
Figure 9 shows the mortality rates across London PCTs for people dying of stroke under the age of 65 years. Figure 9 Standardised stroke mortality rates in persons <65 yrs, London PCTs, London and England, 2004-06
Source: Compendium

Again, rates in SW London are around or below that for London as a whole. In SE London, Lambeth, Lewisham and Greenwich have high rates and Bromley a significantly low rate. Lambeth has the second highest death rate in under 65s in the capital (after Newham). The high rates in under 65s in SE London are a cause for serious concern; most of these stroke deaths should be preventable (see Stroke Prevalence and Prevention chapter (see page 56). Death rates in males and females are discussed later below.

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3.2.9 Numbers of deaths from stroke The previous section considered death rates. This section looks at total numbers of deaths in each borough. Whereas death rates are adjusted for age and sex, there are no adjustments to numbers of deaths. The total number of deaths in a borough is a result of the combined impact of all the predisposing factors, including the effects of age and of population size. As stroke is more common with increasing age, the number of deaths from stroke in any one locality will (amongst other factors) reflect the size of the older population living there. Looking at death numbers can help to assess relative volumes of demand for care. It is possible to have a borough with a low death rate, but very high death numbers in comparison to its neighbours. One such borough is Bromley, as will be seen below. Figure 10 shows the total number of deaths occurring to all residents of London PCTs across the three years 2004 – 2006 for people of all ages (i.e. totals for men and women combined). Figure 10 Number of deaths from stroke, all ages, London PCTs, 2004-06
Source: Compendium

The pattern of death numbers is very different from that of death rates.
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In SW London, the greatest number of deaths occurs in Sutton & Merton PCT (867), which has the highest total in the whole of London by the considerable margin of more than 100 deaths. Croydon has the third highest total (683). These findings contrast with the death rates shown earlier – Sutton & Merton and Croydon rates are average for London. The other PCTs in the sector have numbers of deaths near the middle of the distribution of numbers across London. Lambeth and Lewisham, both of which have very high death rates across all ages, have average numbers of deaths. This reflects their young age profiles as boroughs (see later). In SE London, Bromley has the second highest number of deaths in London (737) despite having a significantly low death rate (Fig 7). Bexley lies fifth in the rank order of death numbers (604). The other SE London PCTs have average totals. Southwark has the lowest total (356) which is less than half the number in Sutton & Merton.

The effects of age – deaths in people under 75 years
Figure 11 shows the total number of deaths occurring in people aged less than 75 years in all London PCTs. Figure 11 Number of deaths from stroke <75 yrs, London PCTs, 2004-06
Source: Compendium

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The totals in this more restricted age group are substantially lower than when deaths at all ages are considered, showing the large contribution to death numbers made by people over the age of 75 years (see also Tables 1 and 2.) In SW London, Sutton & Merton again has the highest total (157 second highest in London) and Croydon is close behind with the fifth highest total (129). The other PCTs have relatively low totals as well as average or low rates of death. Richmond & Twickenham has the second lowest total in London (54) and Kingston the fourth lowest (40). In SE London, the number of deaths under 75 years in Lambeth is the highest in London (167), with Lewisham the sixth highest (127). The other SE London PCTs have average total numbers of deaths in this age group.

3.2.10 The effect of population age profiles The reason why there are twice as many deaths in Bromley as there are in Southwark, despite quite similar death rates can be found in the age profiles of the two boroughs. The age and gender profiles for Bromley and Southwark are shown in Figures 12 and 13. The population age profiles are clearly different – Bromley has many more residents in the older age groups, both men and women, than does Southwark. The gender proportions are much the same between the two boroughs. These charts also show population projections to 2016. The differences in age profile (shown by the overall shape of both profiles) is set to become more marked in future years, suggesting that Bromley will continue to have many more stroke deaths in its residents than will Southwark.

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Figure 12

Population profile of Bromley (including population projection to 2016)

Source: © GLA 2006 Round Population Projections

Figure 13

Population profile of Southwark (including population projection to 2016)

Source: © GLA 2006 Round Population Projections

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3.2.11 Numbers of stroke deaths by diagnostic category and age The number of deaths within each PCT can also be studied by diagnostic category, using a different source of information – VS tables.20 The purpose of considering this data is to understand the proportion of stroke deaths that are due to haemorrhagic causes as opposed to thrombosis, and the proportion that are of undetermined origin. The data also provides information about the proportion of stroke deaths that occur in people under the age of 75 years. This breakdown shows the impact of age on the burden of stroke deaths.

Tables 1 and 2 (on next two pages) show the number of deaths in one year (2007) across SW and SE London, broken down by category of diagnosis derived from death certificate information. These tables show deaths by borough, not PCT, so Sutton and Merton figures are shown separately. The ICD-10 codes I 60 – 62 relate to cerebral haemorrhage.21 Code I 63 relates to death due to infarction22 caused by blockage of the cerebral blood supply. Code I 64 is death due to stroke, unspecified.23 Details of the codes and their definitions are in the Box on Page 23.

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Vital Statistics (VS) tables: issued by ONS, they use death registrations and are based on “original” cause of death. Cerebral haemorrhage: leakage of blood into or close to the brain from damaged or abnormal blood vessel If the brain’s blood supply is interrupted, either by the formation of a clot within a cerebral artery (thrombosis) or by the lodging in an artery of a clot from elsewhere (embolism), brain tissue may die irreversibly. This is called cerebral infarction. Different data sets use different ranges of codes. In this report we have usually used the widest set (I60-I69), to capture all deaths that have a cerebro-vascular cause. Version: Final Page 39 of 106 16/03/09

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Table 1 Stroke deaths 2007 by ICD-10 code -South West London
Note: Figures are for boroughs
All Ages Croydon Kingston Richmond Sutton Merton Wandsworth SW London <75 years Croydon Kingston Richmond Sutton Merton Wandsworth SW London <65 years Croydon Kingston Richmond Sutton Merton Wandsworth SW London >75 years Croydon Kingston Richmond Sutton Merton Wandsworth SW London I60-I69 201 117 110 129 93 119 769 I60-I69 52 18 20 25 10 37 162 I60-I69 22 8 20 9 3 14 76 I60-I69 149 99 90 104 83 82 607 I60-I62 35 15 26 17 16 29 138 I60-I62 22 5 11 9 4 15 66 I60-I62 14 5 11 6 2 7 45 I60-I62 13 10 15 8 12 14 72 I63 27 14 12 4 7 9 73 I63 6 2 0 2 0 7 17 I63 3 1 0 1 0 3 8 I63 21 12 12 2 7 2 56 I64 114 65 51 78 52 51 411 I64 20 9 9 10 5 12 65 I64 4 2 2 1 1 3 13 I64 94 56 42 68 47 39 346 I60-I64 176 94 89 99 75 89 622
I60: Subarachnoid haemorrhage Intracerebral haemorrhage Other non-traumatic intracranial haemorrhage Cerebral infarction Stroke, not specified as haemorrhage or infarction Occlusion/stenosis precerebral arteries not resulting in cerebral infarct* Occlusion/stenosis cerebral arteries not resulting in cerebral infarct∗ Other cerebrovascular diseases Cerebrovascular disorders in diseases classified elsewhere Sequelae of cerebrovascular disease

I60-I64 48 16 20 21 9 34 148 I60-I64 21 8 13 8 3 13 66 I60-I64 128 78 69 78 66 55 474

I61: I62: I63: I64:

I65: I66: I67: I68: I69:

Source: VS tables19

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Table 2 London

Stroke deaths 2007 by ICD-10 code -South East

Note: Figures are for boroughs All Ages Bexley Bromley Greenwich Lambeth Lewisham Southwark SE London <75 years Bexley Bromley Greenwich Lambeth Lewisham Southwark SE London <65 years Bexley Bromley Greenwich Lambeth Lewisham Southwark SE London >75 years Bexley Bromley Greenwich Lambeth Lewisham Southwark SE London I60-I69 179 266 146 108 156 111 966 I60-I69 36 39 39 25 37 33 209 I60-I69 15 18 20 12 19 15 99 I60-I69 143 227 107 83 119 78 757 I60-I62 32 47 39 25 30 30 203 I60-I62 20 18 18 14 16 13 99 I60-I62 12 15 13 8 11 10 69 I60-I62 12 29 21 11 14 17 104 I63 10 48 14 16 17 15 120 I63 2 3 6 3 7 9 30 I63 2 0 2 1 3 3 11 I63 8 45 8 13 10 6 90 I64 91 131 54 41 82 42 441 I64 12 15 10 7 11 6 61 I64 1 2 5 3 4 2 17 I64 79 116 44 34 71 36 380 I60-I64 133 226 107 82 129 87 764
I60: Subarachnoid haemorrhage Intracerebral haemorrhage Other non-traumatic intracranial haemorrhage Cerebral infarction Stroke, not specified as haemorrhage or infarction Occlusion/stenosis precerebral arteries not resulting in cerebral infarct* Occlusion/stenosis cerebral arteries not resulting in cerebral infarct∗ Other cerebrovascular diseases Cerebrovascular disorders in diseases classified elsewhere Sequelae of cerebrovascular disease

I60-I64 34 36 34 24 34 28 190 I60-I64 15 17 20 12 18 15 97 I60-I64 99 190 73 58 95 59 574

I61: I62: I63: I64:

I65: I66: I67: I68: I69:

Source: VS Tables19

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SW London had 769 deaths due to stroke in 2007, whereas SE London had nearly 200 more deaths (966), despite having a smaller population.24 Of all deaths due to stroke, about a quarter to a fifth are due to cerebral haemorrhage (I 60 – 62). Most of the remaining deaths are either due to infarction or are not specified. A death may be unspecified for a number of reasons, ranging from poor form filling after death, to the death being too sudden for precise diagnosis to be made, or because the patient did not receive a CT scan prior to death. The unspecified category is the largest, as is generally the case across the country. Most deaths occur in people over the age of 75 years – there are many less deaths in people under the age of 75 years. In some PCTs there is a five fold difference between the number of deaths over 75 years and the number of deaths under 75 years (e.g. Bexley 143:36). The number of deaths in people under 65 years is even smaller, and is contained within the total of deaths under 75 years. 3.2.12 Deaths and gender By and large stroke death rates in men are higher than in women, both across all ages and in people aged less than 75 years (not shown in this report but available on request). There is however little difference in the rank order of death rates for men and for women across the 31 PCTs of the capital – they are broadly the same as the rates for men and women taken together (see Fig 7). However, when numbers of deaths are considered by gender, a pronounced difference in pattern is seen compared to rates. Figure 14 shows the number of stroke deaths by gender across the three years 2004-06. Figure 15 shows deaths under the age of 75 years.

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Fig 14

Number of stroke deaths by sex, all ages, South London 2004-06
Source: Compendium

Fig 15

Number of stroke deaths by sex, <75 yrs, South London 2004-06
Source: Compendium

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In all boroughs, across all age groups, there are more deaths in women than there are in men. When deaths in men and women under 75 years are considered, the pattern is reversed: there are more deaths in men than there are in women, with one exception – the totals are slightly higher in women under 75 years in Bromley. But elsewhere there are significantly more deaths in men. The excess deaths in men under 75 years is striking in Lambeth, in Sutton & Merton and Croydon PCTs. The explanation is that although death rates in older men are higher than those of women, there are more women living longer than men and so there are more deaths in women across all ages. This pattern of deaths by gender is a common one, and is similar to our findings in NE London.4 3.2.13 Excess deaths in SE London Figure 1 showed that death rates from stroke in SE London have been consistently higher than the London average. It is possible to calculate, for any given year, how many extra deaths have occurred in SE London compared with the total that would have taken place if the sector had the London average death rate. The results for 2006 are shown in Table 3.

Table 3.

Number of excess deaths from stroke in SE London
Excess deaths - persons <75s All Ages 15 63

Excess deaths - males <75s All Ages 15 32

Excess deaths - females <75s All Ages
Source:

1 31

VS tables, indirectly standardised, calculating expected local rates where the study population (SEL) follows London’s overall pattern of stroke mortality.

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These figures could be considered to be target numbers of deaths to be prevented in that year. If SE London were to achieve the London average death rate from stroke (with all other factors staying equal) then the total number of deaths that would need to be prevented, across all ages, works out as 63: 31 female and 32 male. Only 15 of the 63 deaths (24%) would be in people under 75 years, and most (48=76%) of deaths to be prevented would be in people over 75 years. There are very important conclusions to be drawn from this theoretical exercise. Most of the deaths to be prevented would need to be in older people over 75 years of age, and there would be more women than men (in keeping with the sex profile of older people). It is worth remembering that the Vascular Risk Assessment Programme currently being launched by the Department of Health (which includes an objective to reduce incidence of stroke) has an age cut-off of 74 years. This point is explored in more depth in the Stroke Prevalence and Prevention chapter of this report.

3.3 Understanding numbers and rates
3.3.1 Numbers of deaths The size of the total numbers of stroke deaths in any PCT is one indicator of the absolute burden of illness represented by stroke. A further indicator of burden of illness is the number of hospital admissions (see later). We know from our work in NE London4 that PCTs with large numbers of deaths also require large numbers of hospital admissions for acute stroke – as might be predicted. So understanding the death numbers across the sector is important when it comes to planning stroke prevention and also for planning acute and community stroke services. Death numbers is one proxy for absolute need for care. But the numbers of deaths do not of themselves indicate relative need for care. Nor do they indicate what the numbers should be. That indication can only be derived from considering death rates.

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3.3.2 Rates Because death rates are adjusted for age and for sex, a high overall death rate in a PCT does not indicate a large elderly population at risk. It indicates a high risk of stroke death across all ages in comparison with, say, London as a whole. Getting the rate down may be a matter of social justice and health equity rather than an issue simply of reducing the number of stroke deaths. This is easier to grasp when applied to the population under 65 years. The absolute numbers of deaths in this age group is low compared with the numbers across all ages. But if death rates are high in under 65s it may be a priority to work hard to reduce it – as a matter again of equity and fairness. In the under 65 yr age group there is the added issue that stroke death in people of working age may have huge financial implications for the family as well as obvious human cost. So work to reduce death rates in under 65s is justified on these grounds alone, irrespective of the rather small numbers involved. In summary, absolute numbers of deaths indicate recent absolute levels of burden of illness. They do not indicate what the total numbers ought to be. Death rates indicate relative health inequalities, which may need to be addressed on grounds of equity and fairness. It is possible, using comparisons and benchmarks, to agree what the rates ought to be, and thereby to set a target for the numbers. 3.3.3 What this chapter shows Demography People with longer life expectancy and those over 65 years of age tend to live in the more peripheral locations; by contrast deprivation factors are worse towards the centre of the capital, and black and minority ethnic communities are also more concentrated in these more deprived locations. Death rates The mortality section shows that although death rates from stroke are falling across both SW and SE London, the relative position of the two sectors is very different. In SW London, death rates over the last 14 years have been consistently very close to the London average. By contrast, in SE London death rates from stroke have been consistently higher than the London average and have been falling more slowly than the national trend. Ten years ago death rates from stroke in SE London were lower than the national average; now they are higher than the national figure. This difference is even more striking when death rates in people under 75 years

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are considered. This is an important health inequality experienced by people living in South East London. Within SW London, Richmond and Twickenham has consistently low death rate, while other PCTs have broadly comparable rates around the London average. In SE London most PCTs have death rates higher than the London average. By contrast, stroke death rates are consistently low in Bromley (well below the London average). Bromley has the second lowest stroke death rate for people under 75 years in the capital, whereas Lambeth has the highest stroke death rates in London across all ages, as well as in the under 75s. There is therefore an important health inequality within the SE London sector, as well as between the sector and London / England. Numbers of stroke deaths When numbers of deaths are considered, the pattern is quite different. The greatest numbers of deaths occur in boroughs with the average or low death rates. For example, in SW London, the greatest number of deaths in the capital is found in Sutton & Merton (average death rates). In SE London, the greatest number of deaths takes place in Bromley, which has the lowest death rate in the whole of South London. It is essential to grasp this difference and to appreciate what it means. When death rates are very high (e.g. in Lambeth), there is an important health inequality to address. The number of stroke deaths in Lambeth needs to be reduced. However, the absolute number of deaths taking place in Lambeth is not as high as in boroughs with longer life expectancy and greater absolute size. The greatest number of deaths from stroke in SE London is to be found in Bromley, because of its different age profile and its population size. When the number of deaths considered is restricted to people under 75 years, by far the greatest number occurs to residents of Sutton & Merton (SW London) and Lambeth (SE London), with Croydon and Lewisham not far behind. Where people under 75 years are considered, the boroughs with the highest numbers are more likely to be those with the high death rates, because the effects of large numbers of deaths in older people have been excluded. Many more deaths from stroke occur in people over 75 years in comparison with younger groups – in Bexley, for example, four-fifths of all stroke deaths occur in people over 75 years of age. The number of deaths in women exceeds that in men when all ages are considered. Deaths in men, however, exceed those in women for people under75 years in most PCTs.
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Number of excess deaths in SE London If SE London were to achieve the London average death rate from stroke (with all other factors staying equal) then the total number of deaths that would need to be prevented, across all ages, works out as 63: 31 female and 32 male. Most (48, 76%) of deaths to be prevented would be in people over 75 years. Only 15 deaths (24%) would be in people under 75 years. These findings have very important implications for stroke prevention, (see Stroke Prevalence and Prevention section), especially given that the current national vascular screening initiative (see later) has an upper age limit of 74 years.

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4. HOSPITAL ACTIVITY
4.1 What this chapter contains The previous chapter considered the pattern of stroke mortality across SW and SE London. The pattern of deaths may be very different from the pattern of demand for acute care from stroke survivors. This chapter studies patterns of hospital admission across SW and SE London. Numbers of admissions in 2007 are studied both by PCT of residence and admitting hospital, revealing recent patterns of admission across both sectors. Hospital admission rates are also considered, showing whether there is equality of opportunity to be admitted following an acute stroke or transient ischaemic attack across south London. Various other parameters are also considered, such as average length of stay.

Health warning – timeliness of some data
The sources of information used in this section are the latest that were available to us. We have therefore selected only those indicators where some useful conclusions can be drawn. As this report is not a service review, we have therefore not drawn in detail from the findings of the latest National Sentinel Stroke Organisational Audit Report,25 although the information in that report is of course important evidence of service quality for the Cardiac and Stroke Network Boards to consider. Further useful information on local services will be contained in the forthcoming sentinel clinical audit report, due in the spring of 2009. 4.2 Numbers of hospital admissions for stroke Table 4 shows the number of hospital admissions and the range of admitting hospitals for residents of SE and SW London for stroke. There were a total of 2,303 admissions in SW London and 2,545 admissions in SE London during that year. In SW London, the highest total of admissions was from Sutton & Merton (652), and the lowest from Richmond (251). In SE London, the highest total was from Bromley (568) and the lowest from Southwark (377).
25

National Sentinel Stroke Audit - Phase 1 Organisational audit 2008. London: Royal College of Physicians, August 2008.

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Table 4

Number of provider spells for Stroke admissions, by referring PCT and Provider, 2006-7 (ICD10:I60-I69)
Commissioning PCT

Provider Name Dartford and Gravesham NHS Trust Chelsea and Westminster Hospital NHS Foundation Trust Epsom and St Helier University Hospitals NHS Trust Guy's and St Thomas' NHS Trust Hammersmith Hospitals NHS Trust King's College Hospital (Denmark Hill) Kingston Hospital Mayday Healthcare NHS Trust National Hospital For Neurology & Neurosciences Princess Royal University Hospital Queen Elizabeth Hospital NHS Trust Queen Mary's Hospital Queen Marys Hospital (Roehampton) - SW15 5PN Richmond and Twickenham PCT St George's Healthcare NHS Trust Surrey and Sussex Healthcare NHS Trust Tolworth Hospital University Hospital Lewisham West Middlesex University Hospital NHS Trust Other Trusts Total for SE and SW London PCTs

56 0 0 13 0 22 0 0 * * 86 176 0 0 * 0 0 10 0 14 384

* 0 0 12 0 52 0 11 * 382 * 50 0 0 10 * 0 35 0 9 568

* 0 0 * * 34 0 * 6 0 227 35 0 0 * * 0 33 0 8 358

0 * * 147 * 160 0 19 18 0 0 0 0 0 71 0 0 * 0 22 447

0 0 0 19 * 51 0 * * 6 8 * 0 0 * 0 0 300 0 14 411

* 0 * 150 * 158 0 0 17 * * 0 0 0 * * 0 19 0 20 377

0 0 13 * * 8 0 385 * 24 0 0 0 0 77 10 0 * * 13 542

0 0 8 * 17 * 267 0 * 0 0 0 * 0 37 * 87 0 0 8 433

0 7 * * 48 0 106 0 0 0 0 0 23 10 8 0 * 0 37 9 251

0 38 6 15 30 * 50 * * 0 0 0 21 0 248 0 0 0 0 8 425

324 6 * * 31 13 * 0 0 0 0 0 258 * * 0 * 7 652

Source: Hospital Episode Statistics

NB.

A zero means no admissions. * means 5 admissions or fewer

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Sutton and Merton 0 *

Wandsworth

Southwark

Greenwich

Richmond

Lewisham

Kingston

Lambeth

Croydon

Bromley

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These differences in total numbers of admissions per PCT reflect the different sizes and age profiles of the various PCTs, any differences in stroke event frequency, and any differences there may be in admission thresholds. However, it is still currently the case that most stroke admissions from more peripheral PCTs are to local district general hospitals. The pattern shows a strong geographic element, but one that is less striking than in NE London.26 In NE London, we found that over 95% of admissions from any one PCT were to only one or two hospitals, and that those hospitals were always the ones that were nearest. This pattern was clearly determined by the LAS, who in that sector have tended to take all acute stroke patients to the nearest hospital with an A&E department. The pattern of hospital admissions in SW London is not so strikingly geographic as in NE London. From Croydon, most admissions (385) were to Mayday Hospital, but there were a significant total admitted to St George’s (77), even though Mayday is situated in the north of the borough. Kingston shows a similar pattern.27 Most admissions from Richmond were to Kingston Hospital (106), but as many as 48 crossed the Thames to the Hammersmith. Most admissions from Wandsworth were to St George’s Hospital (248) and 50 went south to Kingston, while a small but important total (30) went across the river to the Hammersmith Hospital; 53 others went to teaching hospitals nearer the centre of London. Most admissions from Sutton & Merton were to Epsom & St Helier (325) and St George’s (258), with a smaller number (31) admitted to Kingston Hospital. The pattern of hospital admissions in SE London is rather more based on geography. From Bexley, most admissions were to Queen Mary’s Sidcup (176). There were smaller numbers of admissions to Queen Elizabeth Hospital (86) and to Dartford & Gravesend (56), while 22 went to King’s. Most of Bromley’s stroke admissions were to Bromley Hospital (382) with 52 going to King’s and 50 to Queen Mary’s Sidcup. Most admissions from Greenwich (227) were to Queen Elizabeth Hospital, with 35 each going to King’s and Queen Mary’s and 33 to Lewisham. Most of Lambeth’s stroke admissions were to King’s (165) and Guys & St Thomas’s (147). A significant number went to St George’s (71) and a small number (19) to Mayday, presumably from the south of the borough. Most of Southwark’s stroke admissions were to King’s (161) and St George’s (150) with 19 only going to Lewisham.

26

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This overall pattern shows that although most admissions are to the geographically nearest acute hospital, a significant number of admissions are to teaching hospitals nearer the centre of town. This probably reflects travel times along the main road routes into London – the choice will almost always be made by the ambulance service based on travel times. In SW London there have been local arrangements whereby out of hours and at weekends, the LAS will take acute stroke patients directly to St Georges or another specialist stroke unit, instead of taking patients (for example) to Kingston hospital. This arrangement is reflected in the figures. 4.3 Hospital admission rates Hospital admission numbers (Table 2) show patterns of demand and of events. Hospital admission rates provide another way of comparing hospital admission activity across PCTs.

Figure 16 shows age and sex standardised hospital admission rates for stroke across all London PCTs, compared with London and England as a whole. Figure 16 Standardised hospital stroke admission rates by London borough, London and England – persons, 2006-07
Source: HES

Across London as a whole, PCT admission rates for stroke tend to be higher than the national average.
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The highest hospital admission rates in London are in those PCTs with high stroke death rates – e.g. Tower Hamlets, City & Hackney, Islington and Newham all have admission rates significantly higher than the London average. This suggests that a high admission rate possibly corresponds to a high rate of stroke events. However, on that basis we would expect high admission rates from Lambeth and Lewisham, whereas admission rates for these PCTs are close to the London average. In comparison, Croydon and Richmond & Twickenham (SW London) and Bexley and Bromley (SE London) all have statistically significantly low hospital admission rates in comparison with the London average. These PCTs have low stroke death rates and this could correlate with a relatively low rate of stroke events. 4.4 Admission rate trends Fig 17 shows the trend in hospital admission rates since 2002 in all South London PCTs together. Bromley and Bexley have had consistently low rates throughout this period. Richmond and Croydon’s rates have fallen more recently.

Figure 17

Trends in standardised stroke admission rates, persons, South London PCTs, London and England 2002-07
Source: HES

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What do low or high admission rates mean?
It is not straightforward to explain the variation in hospital admission rates for stroke across South London PCTs. Hospital admission rates for stroke probably correspond to the rates of stroke events occurring (stroke incidence). However, the very high death rates in Lambeth are not correlated with a high admission rate; Kingston has average death rates and high admission rates. The range of variation between PCTs is also striking, with especially low rates in Croydon, Richmond, Bexley and Bromley. It is possible that one additional factor driving hospital admission rates is the threshold of admission. A possible reason for low rates could be a differentially high admission threshold. If GPs in a particular setting are less likely to admit stroke patients, or if carers or patients are less likely to consent to admission, that could explain part of the pattern. This is, of course, conjecture. Anecdotal evidence in Redbridge has suggested that reluctance to admit some stroke patients may be due to concerns about local services and this factor may contribute to low hospital admission rates in that PCT.28 The SW and SE London networks may wish to investigate these issues, engaging local GPs and other clinicians with service users and testing various scenarios, as part of care pathway development. The issues are picked up in the Discussion and Recommendations chapters. 4.5 Hospital admissions for transient ischaemic attack The National Stroke Strategy recognises the important need to move swiftly to manage transient ischaemic attack (TIA); there is a 20% risk of a full stroke occurring within four weeks of a TIA. Those at very highest risk may require a hospital admission. The best way to assess how well TIA is being managed in the sector is through auditing local performance against the main aspects of an agreed care pathway, including speed of access for those patients at high risk. In the meantime we can compare hospital admission rates for TIA across the sector with rates in London and England.
28

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Figure 18 shows the standardised rates for hospital admissions for TIA across both SW and SE London in 2006-07.

Figure 18

Standardised hospital admission rates for TIA, persons, SW and SE London, London and England, 2006-07
Source: HES

In SW London, the admission rate for the sector as a whole is significantly low compared with both the London and national average rates. Sutton & Merton has an extremely low rate. In SE London, the sector as a whole also has a low rate, significantly lower than the national rate; Lambeth has the lowest rate in the whole of South London, by some margin. In contrast, adjacent Lewisham has a very high rate, double the national average. It is not easy to explain these varying rates, without further research (including looking at coding of TIA admissions by provider). But it does suggest that some patients are failing to be admitted in South London when they would have been in other parts of the capital. It is an issue that requires consideration by the two network boards (see Discussion and Recommendations chapters).

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4.6 Length of stay (LOS) in hospital after acute stroke There are a number of length of stay (LOS) parameters that can be used to compare hospital activity – the commonest is the average LOS, (which uses the mean value of the interval between date of admission and date of discharge).

Tables 5 and 6 show average LOS across SW and SE London, compared with London and with England, serially by month up till March 2007. These figures are provided by DMIT.29 Average LOS across both sectors has been steadily falling since 2004. In SW London, LOS has been consistently below the London average – in SE London it has been consistently around or slightly above the London average. Table 5 Monthly average LOS, stroke admissions – SW London, London and England, March 2004-07
Source: DMIT 2008

29

Disease Management Information Toolkit (DMIT). DMIT is a voluntary good practice tool that the NHS may wish to use to strengthen their approach to Disease Management, by presenting data at Primary Care Trust (PCT) level on conditions contributing to high numbers of emergency bed days. DMIT models the effects of possible interventions which may be commissioned at a local level. It aims to support decision-makers, commissioners and deliverers of care for people with LTCs. http://www.dh.gov.uk/en/Healthcare/Longtermconditions/DH_074772

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Table 6

Monthly average LOS, stroke admissions – SE London, London and England, March 2004-07
Source: DMIT 2008

Table 7 shows the figures for emergency bed days, number of admissions and LOS for stroke and TIA combined for both SW and SE London for the four years 2004-07.

DMIT uses a more restricted set of ICD-10 codes than we have, which explains the lower admission totals in these tables compared with totals for 2007 shown in Table 4.
SW London admissions have fallen slightly in the last year shown, consistent with the general trend in London and England. SE London shows a similar pattern, although the total number of admissions and emergency bed days are higher than in SW London. Emergency bed-day totals and average LOS have fallen in both sectors, but most dramatically in SW London, where both emergency bed-days and average LOS fell by more than 20% in the last year for which there are figures.

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Table 7 Emergency bed days, admissions and length of stay - totals for Stroke & TIA

Source: DMIT

Bed days

Admissions

Length of stay

SWL

SEL

London SHA

England

SWL

SEL

London SHA

England

SWL

SEL

London SHA

England

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

6,623 8,598 9,752 8,429 6,619 8,075 8,121 9,194 7,614 9,403 7,112 7,543 4,902 6,708 6,406 6,572 33,402 32,009 31,672 24,588 -22.4%

9,095 11,919 12,786 12,264 8,866 12,682 13,191 12,664 8,119 11,145 10,257 9,855 8,167 9,405 9,977 8,348 46,064 47,403 39,376 35,897 -8.8%

38,057 53,483 54,736 49,786 38,885 53,036 52,318 48,933 40,854 51,278 48,608 46,823 36,554 41,717 45,319 43,004 196,062 193,172 187,563 166,594 -11.2%

336,266 453,352 456,596 440,217 325,232 427,937 423,604 410,611 321,482 408,298 397,337 389,237 301,264 375,224 362,146 364,106 1,686,431 1,587,384 1,516,354 1,402,740 -7.5%

361 359 384 359 431 377 381 380 422 335 385 326 323 330 365 330 1,463 1,569 1,468 1,348 -8.2%

478 501 486 424 445 487 471 449 479 442 462 385 433 421 418 390 1,889 1,852 1,768 1,662 -6.0%

2,010 2,042 2,058 1,843 2,158 2,125 2,102 1,910 2,190 2,023 2,186 1,963 2,123 1,969 2,090 1,950 7,953 8,295 8,362 8,132 -2.8%

19,422 19,295 19,601 17,698 19,299 18,932 18,998 17,750 19,253 18,689 18,855 18,162 18,726 17,975 18,265 17,376 76,016 74,979 74,959 72,342 -3.5%

24 24 26 23 19 21 19 23 23 25 18 20 18 17 15 16 24 21 22 16 -24.1%

25 23 25 26 27 25 27 27 25 24 22 23 25 21 22 20 25 26 24 22 -7.0%

29 27 26 25 24 25 24 24 25 24 22 22 23 19 20 20 27 24 23 21 -11.0%

23 23 22 23 22 22 21 21 21 21 20 19 19 19 18 19 23 21 20 19 -7.6%

2003-04 2004-05 2005-06 2006-07 % Annual change 05-06 to 06-07

2006-07

2005-06

2004-05

2003-04

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4.7 Financial issues related to hospital activity DMIT also provides programme budget calculations, comparing population spending rates for the management of stroke (within the category of cerebrovascular disease) in SW and SE London, London and England for the year 2006-07. These are shown in Table 8, which also shows comparative spend on coronary heart disease and disorders of heart rhythm.

Table 8

National Programme Budget Data 2006/07
Source: DMIT

£ per 100,000 population Programme budget category South West London South East London London SHA England

Problems of Circulation Split into subsets of: Coronary Heart Disease

£11,067,530

£10,262,921

£10,315,722

£12,112,198

£3,029,011

£3,029,495

£3,066,608

£3,863,024

Cerebrovascular disease

£1,568,501

£1,438,923

£1,427,027

£1,590,816

Problems of Rhythm

£586,829

£710,448

£554,938

£716,573

Problems of circulation (Other)

£5,883,189

£5,084,055

£5,267,149

£5,941,785

In both SW and SE London, spend per 100,000 head of population is lower than the national comparator in all categories shown. Especially striking is the lower spend on disorders of rhythm in SW London, in comparison with England (London overall has a low spend). It may be that one of the causes of higher death rates from stroke in parts of both sectors in South London is a relative under-diagnosis or under-treatment of atrial fibrillation.
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It certainly suggests that a coordinated initiative could be required across both sectors to diagnose and treat atrial fibrillation (see Stroke Prevention and Prevalence, Discussion and Recommendations sections). 4.8 What this section shows

Hospital admission patterns
In both sectors, the highest totals of hospital admissions for stroke were from residents of boroughs outside the inner city. This pattern reflects the geographical distribution of people over 65 years, whereby more older people are currently living in outer London locations. In SW London, the highest total of hospital admissions was from Sutton & Merton and the lowest from Richmond. In SE London, the highest total was from Bromley and the lowest from Southwark. The pattern of where stroke patients from SW and SE London are admitted is less predominantly geographic than that we had seen in our earlier study in NE London. In SW London, most hospital admissions for acute stroke were to local acute hospitals, but there were an important number admitted to much more distant specialist hospitals; In SE London, the pattern of destination hospitals was a little more geographically based. This may all simply reflect shorter travel times into central London, compared with journeys across suburbs to more peripheral hospitals.

Hospital admission rates
Admission rates are generally low across both SW and SE London. Croydon and Richmond & Twickenham (SW London) and Bexley and Bromley (SE London) all have statistically significantly low hospital admission rates in comparison with the London average. Kingston, meanwhile, has significantly high admission rates. It is not clear to what extent hospital admission rates may reflect local stroke incidence, or different thresholds of admission after an event. Across both sectors, admission rates for TIA are lower than the London average, suggesting that some patients with more severe TIA may be missing out on appropriate hospitalization. The only striking exception is Lewisham, where TIA admission rates are very much higher than elsewhere in South London. Again, this could be due to local contextual factors or more robust coding.

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Programme budget data & length of hospital stay
Programme budget data suggest that spend on disorders of cardiac rhythm should perhaps be greater in SW London (although London spends poorly on this topic as a whole). Average length of stay for a stroke admission in both SW London is lower than the London average, having fallen recently to less than 20 days (London average: 21 days). Average LOS is a little higher in SE London (22 days).

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5. STROKE PREVENTION AND PREVALENCE
5.1 Introduction Previous chapters in this report have shown the epidemiological patterns of stroke deaths and of demand for acute hospital services for those suffering a stroke. These sections provide an important background for work to try and prevent stroke across SW and SE London. Many strokes are preventable. In this chapter we summarise those factors that increase the risks of an individual suffering a stroke and describe the principles of primary and secondary stroke prevention. We examine the likely prevalence of stroke in SW and SE London, and we model the impact that reducing these risk factors may have on future prevalence, taking into account likely changes in population age profile. This enables us to forecast the extent to which reducing some named risks will impact on future burdens of stroke events across each of the PCTs in SW and SE London. The results may have important implications for healthcare planning in both sectors. Lastly, we review current national and local initiatives to prevent stroke. A way forward for SW and SE London is outlined, explored in further detail in the Discussion section of this Report.

5.2 Risk factors for stroke Stroke is not an inevitable event, even though the risk of stroke increases with age. Age is simply a measure of the number of years of exposure to individual risk factors. Even for elderly people, the evidence suggests that it is always worth treating the major risk factors which increase the likelihood of stroke, but which can be controlled in various ways. The principal factors, other than age, which are associated with an increased risk of stroke, are: • •
30

Previous history of stroke or transient ischaemic attack (TIA) Carotid artery stenosis30

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• • • • • • • •

Hypertension (high blood pressure) Atrial fibrillation (AF) 31 Smoking Diabetes High cholesterol Excess alcohol intake Obesity and poor diet Socioeconomic deprivation

Stroke prevention in people who have not had a previous stroke or TIA is called primary prevention. Stroke prevention in people who have already had a previous stroke or TIA is defined as secondary prevention. 5.3 Secondary prevention of stroke For those who have had a stroke or TIA, current evidence suggests even more rigorous control of blood pressure, cholesterol, diet and lifestyle can reduce the chances of a second event. In addition, those patients who are at especially increased risk of stroke (e.g. people with diabetes who have had a previous event, the addition of anti-platelet agents to reduce blood stickiness (e.g. aspirin) will further reduce the risk of a future stroke.32 People who suffer a TIA are at particular risk of stroke; untreated, 20% of them will go on to suffer a stroke within 28 days.33 The National Stroke Strategy advocates that all patients presenting with a recent TIA or minor stroke should be immediately referred for specialist assessment and investigation. Those at especially high risk should be seen within at the most 24 hours, and some may require hospital admission. Prompt treatment of these high-risk cases can produce an 80% reduction in the number of people who go on to have a full stroke.34

31

32

33 34

Atrial fibrillation (AF) is an abnormal heart rhythm, where the upper pumping chambers of the heart (atria) do not contract properly. It leads to an irregular heart rate and is inefficient, sometimes causing heart failure. There is a significant risk of clots forming in the atria, which can be propelled into the carotid arteries and thence to the cerebral circulation, blocking it and causing a stroke. AF may occasionally be due to rheumatic valvular heart disease, requiring more specific treatment. Most cases of AF are not due to valvular disease, and therefore fit the clinical definition of “non-rheumatic atrial fibrillation.” National clinical guideline for stroke (3rd edition). London: Royal College of Physicians, July 2008. National Stroke Strategy. London: Department of Health, December 2007 Rothwell PM et al. Effect of urgent treatment of transient ischaemic attack and minor stroke on early recurrent stroke (EXPRESS study): a prospective population-based sequential comparison. Lancet 2007; 370: 1432-42. Version: Final Page 63 of 106 16/03/09

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5.4 Primary prevention of stroke The following primary risk factors can be treated clinically or managed through lifestyle modification: • • • • • • • • Carotid artery stenosis Hypertension Atrial fibrillation (AF) Smoking Diabetes High cholesterol Excess alcohol intake Obesity and poor diet

All, apart from AF, are also risk factors for coronary heart disease (CHD) and so health promotion initiatives to reduce CHD can also have an impact on stroke. However, certain factors are more associated with primary stroke risk than others, especially hypertension, AF and smoking. We attempt to quantify the potential benefits from interventions to reduce some of these factors later in this chapter. Both hypertension and AF can be managed and controlled. With lifestyle modification and modern antihypertensive medication it is usual to be able to keep blood pressure below a level of 140/90 mm, even in elderly patients. In some patients, AF can be reverted to normal rhythm with drugs or surgery. Those whose AF persists are at risk of stroke, from the propulsion of clots into the cerebral arterial circulation. This type of stroke can be prevented in most patients by the use of anticoagulant medication. Although there is a small risk of haemorrhage, it is now accepted, on the balance of risks, that anticoagulants are highly effective overall at reducing the risk of stroke, although the specific risks for each individual always need to be taken into account. The benefits of stopping smoking apply irrespective of how long a smoker has smoked, and regardless of his / her age. All PCTs now have smoking cessation programmes, with a range of local services to support smokers who wish to quit. Primary care teams could play an even larger role than they do currently.
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Similarly, evidence supports the use of cholesterol-lowering medication for people of all ages, if the extent of any lipid abnormality is severe enough and provided that there is a low risk of side effects for any one individual. Cholesterol measurement is one of the QOF indicators for the GP care of people who are at increased risk of stroke, or who are already on the stroke register. Lastly, good diabetes control has been shown to reduce the risk of cardiovascular complications at all ages.35

Table 9 (next page) shows the costs of different interventions to reduce stroke. Although the source data is from 2000 (so that the absolute costs are now different) their relative values and the “numbers needed to treat” are useful for comparison. All these interventions will reduce the chances of stroke in people who have risk factors but who have not had a previous event.

35

National clinical guideline for stroke (3rd edition). London: Royal College of Physicians,
July 2008.

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Table 9

Cost of interventions to prevent one stroke per year
Source: LHO 200836

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5.5 Stroke Prevalence Previous chapters have shown patterns of stroke death and of hospital admissions (a proxy for stroke incidence). This section considers the proportion of people living with stroke at any one time (prevalence). Prevalence figures include everyone who has had a stroke at some point in their lives – both those who have recovered completely and others who may be in need of acute or more chronic care. Stroke prevalence provides an indication of the total burden of people living with current or past stroke illness in a community. Once prevalence has been determined, it is also possible to predict the impact of stroke prevention initiatives over time on the burden of stroke illness. We have therefore modelled likely stroke prevalence across SW and SE London, and assessed the possible impact of different prevention scenarios. 5.6 Quantifying likely stroke prevalence The main source of information usually used to establish stroke prevalence is the Health Survey for England.37 A model has been developed by Imperial College London and the Association of Public Health Observatories (APHO). It uses pooled data from the 2003 and 2004 Health Surveys for England (HSfE). Because the HSfE has shown that stroke prevalence varies with ethnicity,38 it was necessary to use 2004 Survey data, which includes an ethnic minority boost. HSfE informants are classified as having a stroke if they reported having a stroke that was confirmed by a doctor (“patient-reported, doctor-diagnosed”). This definition has been shown to be the most accurate measure of stroke

37

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The Health Survey for England (HSE) comprises a series of annual surveys beginning in 1991; part of an overall programme of surveys commissioned the DH and designed to provide regular information on various aspects of the nation's health. All surveys have covered the adult population aged 16 and over living in private households in England. Since 1994 onwards the survey has been carried out by the Joint Survey Unit of the National Centre of Social Research and the Department of Epidemiology and Public Health at University College London. Craig R, Mindell J. Health Survey for England 2006: Volume 1 CVD and risk factors adults, obesity and risk factors children. Information Centre for Health & Social Care [2008 [cited 2008 Nov. 26]; Available from: URL:http://www.ic.nhs.uk/webfiles/publications/HSE06/HSE%2006%20report%20VOL% 201%20v2.pdf Version: Final Page 67 of 106 16/03/09

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diagnosis, short of confirmation from medical records,39 and has been used as the basis for calculating stroke prevalence across South London. 5.7 Methods Using patient-reported doctor-diagnosed stroke, a multinomial logistic regression model was fitted to estimate odds ratios. The local stroke model (which includes only those variables that are available locally at population level i.e. age, sex, ethnicity, smoking status and deprivation score) has been applied to Local Authority (LA) data to create prevalence estimates of stroke in those aged 16+ for 2005–2020. Models for PCTs have also been created for 2006-2020 by transforming the same data. Further methodological detail is available at: http://www.erpho.org.uk/viewResource.aspx?id=18054 . 5.8 What we found The modelled prevalence of stroke in South London PCTs is shown in Table 10 below. This shows prevalence for each PCT in 2006 and projected forwards to 2010, 2015 and 2020. Table 10: Modelled prevalence of stroke (16 yrs+ population) in South London PCTs

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Current prevalence is estimated to lie between 1.47% in Wandsworth and 2.38% in Bromley, both of which are below the England prevalence rate of 2.45%. The main reason for this is the differing age structures of the population in London, which tends to be younger, thereby diluting the overall prevalence. It can also be seen that if all other factors remain the same, stroke prevalence will automatically increase in every PCT over the next 12 years, adding significantly to the burden of stroke care likely to be needed.

5.9 Modelled stroke prevalence and prevalence in GP stroke registers We have compared stroke prevalence as determined in the prevalence model with studies performed elsewhere and also with stroke prevalence shown in GP stroke registers.

Other stroke prevalence studies
There have been three recent published UK stroke prevalence studies. A point prevalence study using postal questionnaires (n=18,000) in northern England found that prevalence increased with age and, apart from the very elderly, males had a higher prevalence than females.40 Overall prevalence was found to be 4.7% (95% CI 4.3-5.2%). Full recovery from stroke was reported by 23% of respondents. A two-stage point prevalence study in Newcastle used a valid screening questionnaire to identify stroke survivors from a stratified sample.41 This was followed by assessment of stroke patients with scales of disability and handicap. The overall prevalence of stroke was found to be much lower at 1.75% (95% CI 1.7-1.8). The prevalence of stroke-associated dependence was 1.17%. The third survey was of particular interest as it was carried out in South London. All incident cases of neurological disorders were ascertained in 13 general practices in South London.42 A population of 100,230 patients registered with the practices was followed prospectively for the onset of
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Geddes JM, Fear J, Tennant A, Pickering A, Hillman M, Chamberlain MA. Prevalence of self reported stroke in a population in northern England. J Epidemiol Community Health 1996; 50(2):140-143. O'Mahony PG, Thomson RG, Dobson R, Rodgers H, James OFW. The prevalence of stroke and associated disability. J Public Health 1999; 21(2):166-171. MacDonald BK, Cockerell OC, Sander JWAS, Shorvon SD. The incidence and lifetime prevalence of neurological disorders in a prospective community-based study in the UK. Version: Final Page 69 of 106 16/03/09

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neurological disorders, using multiple methods of case finding. Lifetime prevalence rates were: completed stroke 0.9% (CI: 0.8-1.1); and for transient ischaemic attacks 0.5% (CI: 0.4-0.6%). These rates are noticeably lower than our modelled prevalence estimate of 2.45% for England as a whole. There is growing evidence that a significant proportion of patients with stroke are not yet on GP stroke registers (see below), which explains the lower prevalence found in this study.

Chart 1 shows a comparison between stroke prevalence in our model and prevalence in GP stroke registers recorded in QOF. All figures are for 2006-07.

Chart 1: QOF-registered and expected stroke prevalences

2.5% 2.0% 1.5% 1.0% 0.5% 0.0% le y

QOF-Registered Prevalence

Expected Prevalence

yd on Gr ee nw n up ich on Th am es La m be th Le w ish am

Ki ng st o

If the modelled estimates are accurate, it appears that only 31% to 67% of stroke cases are QOF-registered. Most PCTs show QOF stroke prevalence rates of less than 1%, which is noticeably lower than most other stroke prevalence studies. Some of these “missing” stroke cases may be known to the practice to have had a stroke e.g. receiving prescriptions for secondary prevention, but do not yet have diagnoses entered. Some may be unknown (at least electronically) to the practice either because hospital discharge information has not been received or noted/entered, or because the stroke occurred while under the care of another GP.

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Map 7 shows the geographical distribution of observed/expected stroke prevalence across South London. The higher this ratio (darker green on the map) the close observed prevalence is to that expected from our model. These ratios are highest in Bromley and Bexley, and lowest in Richmond and Greenwich.

Map 7

5.10 Quantifying the impact of risk factors on stroke prevalence The stroke prevalence model also identifies the main risk factors for stroke and their relative impact on stroke prevalence. These are shown in Table 11. (They do not include atrial fibrillation, because its prevalence is not assessable in the HSfE.)

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Table 11: Risk factors for stroke from prevalence model

Risk factor Age 45-54 Age 55-64 Age 65-74 Age 75+ Ever had high BP Used to smoke regularly Current smoker BMI 25-30 GHQ12 Score=4 GHQ12 Score=5 GHQ12 Score=9 GHQ12 Score=10[worst psychosocial health] Limiting long-term illness Non-limiting long-term illness No long-term illness

Relative Risk 2.907 5.724 15.196 21.734 2.767 1.392 1.638 0.494 2.192 2.710 3.814 2.586 1.000 0.387 0.291

p value 0.051 0.001 <0.001 <0.001 <0.001 0.028 0.006 0.039 0.005 <0.001 <0.001 0.035

95% CI 0.995 2.022 5.397 7.672 2.106 1.037 1.150 0.252 1.267 1.580 1.989 1.070 8.499 16.207 42.787 61.571 3.635 1.868 2.333 0.966 3.791 4.647 7.312 6.250

<0.001 0.278 <0.001 0.207

0.539 0.410

The first column shows the risk factors, and the second column shows the relative risk (RR).43 A figure of 1.0 would constitute a baseline level of risk; a risk of 2.0 would signify twice the baseline risk. The third and fourth columns show the statistical p value and the confidence intervals.44 The higher the RR value, the greater the relative risk of stroke associated with that risk factor. The table shows the extent to which age is a risk factor for stroke, the relative risks increasing with each age band. The risk escalates sharply after the age of 65 years, and more sharply still after age 75 years. Obesity (a BMI of >30) was not identified as a risk factor (whilst being overweight [BMI 25-30] was). This may have been because of the low prevalence of obesity in older age groups. The GHQ12 score45 is a measure of
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Risk reduction in this table is Relative Risk Reduction. For technical reasons this can be considered as being the same as an odds ratio (OR). OR of 1.0 = baseline risk; OR of 2.0 = twice baseline risk, etc. p value: statistical significance is achieved where p<0.05 95% Confidence Intervals: The range of values within which we can be 95% certain the correct value should lie. GHQ12: General Household Questionnaire score (12 domains) measures respondents’ assessment of their general health and wellbeing Version: Final Page 72 of 106 16/03/09

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psychological wellbeing; the higher its score, the worse the respondent’s health. The GHQ12 may be acting as a confounder, i.e. is independently associated with stroke as a result of the condition, rather than indicating a cause. Having a limiting long-term illness is associated with an increased stroke risk, but again may be a confounder. Having “no limiting long-term illness” is predictably inversely associated with risk of stroke. Of the risk factors shown, the main preventable risks are these: • • • Smoking Hypertension Overweight.

5.11 Atrial Fibrillation Other studies have shown that atrial fibrillation (AF) is an important stroke risk factor. In the Framingham study, AF was associated with a 50% increase in all-cause death rates in men and a 90% increase in women.46 Treatment with long term anticoagulation or antiplatelet treatment in patients with AF is very effective. AF is important to recognise in clinical practice because it is often undiagnosed, and the stroke risks can be substantially reduced. Prevalence of AF ranges from 0.1% among adults younger than 55 years to 9.0% in the over 80s.47 The commonest causes of AF are CHD, hypertension, and mitral valve disease. The relative importance of valve disease in atrial fibrillation has diminished over time, and as a result, hypertension has become the most common, and the most addressable, risk factor for atrial fibrillation. It is not possible to estimate the prevalence of AF from the HSfE. Instead we have obtained estimates of AF prevalence from the NHS Comparators website48 from which we have calculated expected prevalence figures for SW and SE London PCTs. These expected figures can then be compared with

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Benjamin EJ, Wolf PA, D'Agostino RB, Silbershatz H, Kannel WB, Levy D. Impact of atrial fibrillation on the risk of death: the Framingham Heart Study. Circulation 1998; 98:946– 952. Go AS, Hylek EH, Phillips KA, Chang YC, Henault LE, Selby JV, Singer DE. Prevalence of diagnosed atrial fibrillation in adults: national implications for rhythm management and stroke prevention: the AnTicoagulation and Risk Factors In Atrial Fibrillation (ATRIA) Study. JAMA. 2001;285:2370-2375. http://www.ic.nhs.uk/nhscomparators Version: Final Page 73 of 106 16/03/09

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those observed from information obtained from GPs’ Quality and Outcome Framework (QOF) returns from the same PCTs.

Table 12 shows observed (O) and expected (E) prevalence of AF, expressed as a ratio (O/E) and as a rate difference (O-E).

Table 12

Prevalence of atrial fibrillation in South London PCTs (2006-07) Ratio Observed Expected (O) (E) (O/E) 0.93 1,809 1,944 0.81 3,120 3,837 0.88 3,776 4,286 0.99 2,089 2,104 O–E -135 -717 -510 -15

PCT Kingston Croydon Sutton & Merton Richmond & Twickenham Bromley Bexley Greenwich Lambeth Lewisham Southwark ENGLAND

1 0.93 0.89 0.72 0.76 0.76 1.02

4,362 2,691 2,107 1,920 1,916 1,699 700,998

4,350 2,885 2,368 2,655 2,523 2,238 684,402

12 -194 -261 -735 -607 -539 16,596

Most PCTs have a QOF-registered prevalence of AF that is below what we would expect. Bromley is the only exception. We suspect that this rather crude model underestimates AF prevalence, in which case the gap between expected and observed prevalence will be rather greater. 5.12 Attributing future stroke prevalence to individual risk factors The contribution each risk factor makes to overall stroke prevalence can be estimated by calculating population attributable risk (PAR).49

49

Population attributable risk: measures potential impact of control measures in a population. It is defined as PAR= (prevalence exposure (RR-1))/(1+ prevalence exposure(RR-1)) where RR = relative risk. Because stroke is a comparatively rare outcome, we can assume RR= OR (odds ratio from the above table).

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The PAR of smoking for stroke in England is 13.3% and of hypertension 34.8%. Thus about half the risk for stroke is preventable from controlling these two risk factors together, without considering the additional contribution of atrial fibrillation or obesity. 5.13 Predicting the impact of risk factor reduction on stroke prevalence It is possible to use the stroke prevalence model and the PAR estimates to predict likely impact of reducing two important risk factors by differing extents – hypertension and smoking. We have modelled the impact of four feasible primary prevention scenarios on stroke prevalence for this Report:50 • Scenario 1a assumes that smoking prevalence falls by 1% from the current level by 2010, a further 1% by 2015 and a further 1% by 2020, but the prevalence of hypertension is unchanged. Scenario 1b assumes that the prevalence of hypertension is reduced by 3% over each five-year period, but the prevalence of smoking is unchanged. Scenario 2a assumes that smoking prevalence falls by 2% from the current level by 2010, a further 2% by 2015 and a further 2% by 2020, but the prevalence of hypertension is unchanged. Scenario 2b assumes that the prevalence of hypertension is reduced by 6% over each five-year period but the prevalence of smoking is unchanged. Scenario 3 assumes that smoking prevalence falls by 1% from the current level by 2010, a further 1% by 2015 etc, and that the prevalence of hypertension is reduced by 3% over each five year period Scenario 4 assumes that smoking prevalence falls by 2% from the current level by 2010, a further 2% by 2015 etc, and that the prevalence of hypertension is reduced by 2% over each fiveyear period.

•

•

•

•

•

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The HSfE does not have a large enough sample to produce risk factor prevalence estimates below Regional level. However synthetic estimates of local smoking prevalence can be obtained from the Neighbourhood Statistics website. Hypertension prevalence estimates have been obtained from the local prevalence model on the APHO website. (It is not possible to calculate a PAR for AF as no odds ratio (RR) is available for this risk factor.) Version: Final Page 75 of 106 16/03/09

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An example of the impacts is shown in Chart 2 (Bexley PCT); other PCT charts (and charts for both SE and SW London sectors as a whole) are in the Annex at the end of this chapter. Charts of national trends in smoking and hypertension prevalence are also included.

Chart 2

Stroke Prevalence scenarios, Bexley PCT

5000

Stroke prevalence prevention scenarios: Bexley PCT
4800 4600 e k o4400 r t s f o s e4200 s a c t n e l 4000 a v e r p f 3800 o s r e b 3600 m u N 3400 3200 3000 2006 2010 2015 2020

No change Scenario 1- hypertension 3% decrease/5 years Scenario 1- smoking 1% decrease/5 years Scenario 2- hypertension 6% decrease/5 years Scenario 2- smoking 2% decrease/5 years Scenario 3- small decrease both Scenario 4- larger decrease both

The figures shown on the vertical axis are the predicted prevalence numbers for the PCT concerned – (i.e. number of individuals in that PCT who will have be living having had a stroke by the year concerned). It can be seen that in the absence of a change in risk factors, a substantial increase in stroke numbers is expected as the population ages. Reductions in smoking prevalence would reduce the rate of stroke increase, but changes in hypertension prevalence would have greater impact. Best impact can be achieved in Scenario 4 (serial reduction of 2% in smoking, plus 2% reduction of hypertension every five years). In this scenario, in Bexley stroke prevalence would have fallen slightly between 2006 and 2020.

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The reason for this is the dominant impact of demographic change between now and 2020 across the whole of South London. The important element of that change is the increase in population age during the period. Age is a very powerful determinant of overall stroke risk, and the prevalence model shows that it will have a dominant impact on future stroke prevalence unless there is a significant reducing effect from smoking cessation or better blood pressure control. 5.14 Comment on time lags We have not incorporated any time lags for the effects of prevention greater than five years in the model because there is evidence that reduction in CVD risk occurs rapidly after smoking cessation or control of hypertension. The US Nurses Study showed that the risk decline after smoking cessation occurred for CHD and total CVD within two years, and for stroke after 2-4 years.51 Similarly, the Japanese JACC study showed that for mortality alone, much of the reduction in the excess risk were realized within the first five years for CHD disease and stroke.52 Sixty-one percent of the full potential benefit of quitting in regard to CHD mortality and 42% of the full potential benefit of quitting in regard to stroke mortality was realised within the first 5 years of quitting smoking. There is less evidence about risk reduction rates after control of hypertension, but it is biologically plausible that this happens quite quickly. The hypertension model uses as an outcome of overall hypertension (treated controlled, treated uncontrolled and untreated). A rapid reduction in overall prevalence would only result from improving management of treated hypertension and finding new cases of established hypertension, and not from “primordial” prevention e.g. by increased physical activity. In other words, a rapid reduction in overall stroke prevalence requires clinical action in addition to broad population health improvement initiatives. This is an important issue, explored further in the Discussion chapter in this report. 5.15 Stroke Prevention through management of high blood pressure The section above showed the possible impact on future stroke prevalence of effective hypertension management. One issue affecting stroke prevention is that of undiagnosed cases of hypertension.
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Iso H, Date C, Yamamoto A, Toyoshima H, Watanabe Y, Kikuchi S et al. Smoking Cessation and Mortality from Cardiovascular Disease among Japanese Men and Women: The JACC Study. Am J Epidemiol 2005; 161(2):170-179. Kenfield SA, Stampfer MJ, Rosner BA, Colditz GA. Smoking and Smoking Cessation in Relation to Mortality in Women. JAMA 2008; 299(17):2037-2047 Version: Final Page 77 of 106 16/03/09

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We examined the likely completeness of GP hypertension registers across South London. Chart 3 shows expected prevalence of hypertension in South London boroughs53 in comparison with QOF-registered prevalence. Since most patients on treatment (either controlled or uncontrolled) should be QOF registered, most of the gap is probably made up of undiagnosed cases. This is a national issue, not one confined to South London.
Chart 3: Observed and expected prevalence of hypertension, South London LAs

Chart 2: Observed and expected prevalence of hypertension, S London LAs
30% QOF-registered prevalence 25% Expected Prevalence

20%

15%

10%

5%

0%

Although stroke is concentrated in older people because of long exposures to risk, hypertension is quite common in younger age groups, who are less likely to have had their blood pressure measured, especially males. It is also more common in certain BME groups such as Black African and African-Caribbean men. This is important for stroke prevention work, especially hypertension case-finding in some south London communities. Chart 4 shows the proportion of London-registered patients (denominator population 440,000) on the QRESEARCH database54 who have had their BP measured recently. Men lag way behind women in younger age groups, especially around 25-34 years, although the gap narrows progressively with older age groups.
53

The information is also available on request at PCT level QRESEARCH is a consolidated database held by the University of Nottingham and derived from anonymised health records of 11 million patients from 574 practices using the EMIS computer system. Version: Final Page 78 of 106 16/03/09

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This shows the importance of ensuring that men have their blood pressure measured.

Chart 4: percentage of people aged over 16 years on GP register, with a systolic BP recorded in the last 27 months, 2006-7
100 90 Percentage with systolic BP recorded 80 70 60 50 40 30 20 10 0 0-15 16-24 25-34 35-44 45-54 55-64 65-74 75+

London Female London Male

5.16 How to assemble coherent stroke prevention programmes across SW and SE London Although the interventions that can reduce risk of stroke are themselves evidence based, putting a programme together that will have effective impact for a particular local population is more complex. For any stroke prevention programme to be effective, it has to have both reach and impact: it must influence health behaviours and health services across diverse communities, some of whom are hard to reach. In addition, there is a need for initiatives that integrate awareness of stroke risk (and what can be done to reduce it), with awareness of how to recognize stroke/TIA and what to do to obtain prompt and effective treatment. For example, it makes sense for social marketing initiatives to combine both messages – the need for stroke prevention and the need for prompt action to obtain treatment in an acute event. Below, we briefly consider national and regional stroke prevention initiatives, which are current drivers for PCTs in their requirement to reduce health inequalities and prevent cardiovascular disease, including stroke. We also

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raise some concerns about their likely impact, issues raised further in the Discussion chapter and in Recommendations. 5.17 National guidance and initiatives Stroke prevention forms part of the National Stroke Strategy,55 with a Quality Marker specific for prevention (see box below):

More recently (April 2008) the Government announced a national programme to screen the whole population for cardiovascular risk factors in general, in order to detect risk factors for coronary heart disease, stroke, diabetes and renal disease. Putting Prevention First56 moves the national service framework agenda away from treating disease to that of primary prevention. The details of the programme are based on epidemiological and economic modelling performed by the vascular team at the Department of Health. The proposal (endorsed by the National Screening Committee) is for everyone between the ages of 40 and 74 years to be invited for cardiovascular screening once every five years. The concept is one of a vascular clinical check-up performed in a variety of possible settings; but once abnormalities have been found, the expectation is for patients to be followed up and risk factors addressed by the GP team with

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National Stroke Strategy. London: Department of Health, December 2007. Putting Prevention First. Vascular checks: risk assessment and management. London,
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whom they are registered. The Department of Health team have assumed that most face-to-face interventions would be performed in general practice. The charts shown suggest that many cases of hypertension will be detected in this population. However uptake is expected to be lower in deprived areas unless PCTs devote more resources to contacting these populations.

The model recommended by the Department is reproduced in the graphic on page 82. The problem of age range
Although the Vascular Risk Assessment programme has an official objective of reducing stroke, the age range targeted has an explicit cut-off of 74 years. If the programme delivers as it is intended, there should eventually be a reduction in stroke incidence as the years go by. However, in the short term the impact is likely to be less than that required. The reason for this is that the overwhelming majority of strokes and stroke deaths occur in people aged 75 and above (see Epidemiology chapter of this report). In SW London in 2007, 79% of stroke deaths were in people over 75 years of age. In SE London, the proportion was 78%. If any of these deaths were preventable (from better diagnosis and control of hypertension and AF, for example) none of them would have been prevented through the Vascular Risk Assessment Programme. Only around 20% of stroke deaths occurred in the population to be targeted by the Vascular Risk Assessment Programme. In SW and SE London, stroke prevention programmes will need to be expanded to ensure coverage of older people; the vascular risk assessment programme will not deliver stroke prevention on its own in the short to medium term. This issue is picked up in more detail in the Discussion chapter and in Recommendations.

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5.18 Vascular Risk Assessment; Department of Health’s approach

Source: Putting Prevention First – London: Department of Health, April 2008

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5.19 Stroke Prevention in London – the role of Healthcare for London While the Stroke Strategy for London was being prepared for publication, a technical appendix was released for consultation, addressing stroke prevention.57 This document is referenced in the strategy as a web-based resource. The document builds on the evidence we have described above, describing those risk factors that are important to reduce. It emphasizes the benefit of social marketing and explains that PCTs will be expected to develop their own local programmes to prevent stroke. The Healthcare for London stroke prevention paper makes no mention of the need to target, amongst other groups, people over the age of 75 years. The paper concentrates mostly on performance indicators within the QOF contract for GPs, recommending a series of these indicators for monitoring of effectiveness of local prevention programmes. Whilst it is important to understand how best to monitor stroke prevention initiatives undertaken in general practice, unless GPs are encouraged to do at least some of their stroke prevention work with people over 75 years, the programme will not achieve its main objective.

5.20 The Case for Preventing Stroke in London The Healthcare for London stroke prevention paper also drew on the findings of a London-wide study published in 2008.58 This emphasised the need for work to educate what was termed the “health-illiterate” – those populations most at risk of stroke, but whose communities do not necessarily have the same understanding of the benefits of a healthy lifestyle as other better informed communities. We believe this study to have some relevant limitations. In particular it shows the relationship between high stroke death rates and high rates of hospital demand, but does not consider the impact of age on where most strokes occur. Again, this is a study where it has not been understood that the localities and communities where most strokes and stroke deaths are taking place are not
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Stroke Prevention Strategy. Healthcare for London, 14 October 2008. The Case for Preventing Stroke. London Health Observatory Executive Briefing. London:
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the inner city communities with the highest death rates. Similarly, those inner city communities who have the highest emergency hospital admission rates for stroke are not the communities where the largest numbers of hospital admissions are originating. The reason for this misunderstanding and misinterpretation is the confusion caused by muddling death rates with death numbers. This confusion is explained and hopefully resolved in the Mortality section of this report (see page 22). 5.21 Treatment of hypertension and atrial fibrillation in older people Despite the increased complexity of clinical decisions involving older patients, the evidence suggests that treatment of hypertension is still worthwhile in this group, including treating hypertension in people over the age of 80 years. This was reinforced by the recent findings of the HYVET (Hypertension in the Very Elderly Trial) which showed a reduction of 39% in fatal stroke, in all cause mortality by 21%, cardiovascular death by 23% and cardiac failure by 64%.59 It is also now accepted that atrial fibrillation should usually be treated in older patients within the limits of balancing benefits and risks. Age should not of itself be a barrier to considering clinical interventions to reduce risk of stroke in older people. This is reinforced in NICE guidance on the management of hypertension, which recommends that practitioners should:

Offer patients over 80 years of age the same treatment as other patients over 55, taking account of any comorbidity and their existing burden of drug use. 60 (Evidence Band A [highest quality])
5.22 Preventing stroke in older people (over 75 years) – a local case study for this report A well-organised general practice team will normally see most of its older patients at least once in a 12 month period. Many of them will already have had some of their cardiovascular risk factors assessed, although there is currently no special incentive for this to be done systematically in older people who are not already on the practice’s hypertension, CHD or stroke register.

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It is the systematic aspect that is key to reducing stroke risk across a whole general practice population. The 1990 GP contract introduced the concept of an “older people’s check-up”, on invitation. This was however subsequently dropped from the contract framework, and it has not been replaced within the current QOF arrangements. To understand how much resource would be needed to achieve good coverage of cardiovascular screening in people over 75 years, one of us (JH) approached three GPs currently in practice in different locations across South London. Two GPs agreed to study what proportion of their registered patients over 75 years had attended the surgery in the previous 12 months, and to assess the degree to which their risk factors were already known.

Practice A (SE London) - 719 patients over 75 years, of whom • • • • 93% had been seen in the last year 81% had had a BP check in the last year, (88% last two years). 72% had a cholesterol recorded 9% had AF (at some time).

Practice B (SW London) - 424 patients over 75 years, of whom • • • 92% had been seen in the last year 90% had had a BP recorded in the previous 15 months 55% had a cholesterol measurement.

The third GP took us through his information system, which showed similar results, (including a crude AF prevalence of around 8%) but also revealed how easy it would be (using software linked to his practice EMIS system) to identify which patients needed to attend to have risk factors assessed, and which factors needed to be targeted. These snapshots show that most older patients in need of risk factor assessment are easy to identify, and the number needing a more recent cholesterol, blood pressure or pulse rate measurement was relatively small and manageable in these practices (list sizes approx. 10,000).

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5.22 Summary – what this chapter shows Stroke can often be prevented through control of blood pressure, atrial fibrillation, smoking and other recognized risk factors. It is possible to use information on the known prevalence of these risk factors, and of the prevalence of stroke in SW and SE London, to model future stroke prevalence across the sectors under different prevention scenarios. We have applied our model to SW and SE London PCTs. (It can be used by individual PCTs to test future stroke prevalence under different assumptions, and is separately available.) The model shows that stroke prevalence is under-estimated in GP information systems: QOF reported prevalence has been consistently about 30% below that in our model, in all locations and is, we believe, a poor predictor of service need. We have shown the relative impact of different risk factors and population demography on stroke prevalence over time. This reveals that in most PCTs in SW and SE London, stroke prevalence is due to increase markedly between now and 2020. This increase may be offset if smoking and hypertension prevalence can be reduced; the extent of the offset depends on the PCT concerned and the amount by which smoking and hypertension can be controlled. If control is poor, future stroke prevalence is set to increase significantly between now and 2020. This has profound implications for service planning (see Discussion and Recommendations chapters). The under-recording of stroke prevalence across all PCTs (and most, if not all practices) suggests that case finding would be worth considering. The prevalence model could be applied to individual practices, and case finding support offered where there is a large gap between expected prevalence and prevalence registered through QOF. Current national stroke prevention initiatives, to be rolled out by PCTs from April 2009, are targeting people between the ages of 40 and 74 years. It is important for local programmes to include case finding for hypertension and atrial fibrillation within this age group. Early diagnosis and treatment of hypertension in Black African and African-Caribbean men is epecially important, and a priority in parts of south London where there are large BME communities. However, guidance from Healthcare for London and the London Health Observatory has failed to recognise the fact that nearly 80% of stroke deaths occur in people over the age of 75 years.

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The key point is that so many stroke events and stroke deaths occur in people over 75 years, that unless some prevention work targets older people, it will not succeed in reducing stroke incidence very much for several years yet – until the population currently in their forties, fifties and sixties benefits in future years from stroke risk reduction initiatives now. Three snapshot studies in south London suggest that general practice teams could quite easily screen their population of patients over 75 years of age, most of whom are regularly seen by their practice team in any event. An initiative to screen older people in this way in general practice is feasible and would probably prevent more strokes in the next few years than solely screening people between the age of 40 and 74 years. It is essential to do both. (See Discussion and Recommendations chapters).

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6. COMMISSIONING
At the request of the two Cardiac and Stroke Network Boards, we have reviewed the Collaborative Commissioning Intentions (CCI) for Stroke (2008) for both SW and SE London (see also Objectives, page 13). The documents reflect the current stroke agenda of Healthcare for London, with considerable emphasis on acute and hyper-acute services, and on stroke rehabilitation. These are crucial areas for future development of stroke services in London, but both lie outside the agreed scope of this report. 6.1 Epidemiology background Both documents contain some public health data as background. In the SW London CCI, incidence and prevalence figures are presented. Incidence is actually difficult to determine, and we have not presented incidence figures in this report. The prevalence figures in the CCI guidance are about half the estimated figure we have calculated from our prevalence model (see Stroke Prevalence and Prevention chapter). The SE London CCI document uses prevalence figures drawn from GP QOF data. As explained in the Prevalence and Prevention chapter, GP stroke registers underestimate prevalence by at least 30%. The CCI document also shows numbers of hospital admissions by PCT. We suspect that the range of ICD-10 codes used is more restricted than in our report. We believe that there are arguments for use of a wider coding set – see Discussion chapter. We would suggest that a standard dataset be used as background for stroke policy initiatives, to avoid confusion. The sources used in this report are nationally benchmarked and should provide the best framework for this. 6.2 Stroke Prevention Both CCI documents contain advice for PCTs on stroke prevention. Both refer to the national Vascular Risk Assessment programme to be rolled out from April 2009. There is no clear service model recommended – guidance from the Department of Health was not issued until November 2008.61 The SW London CCI advice suggests that prevention initiatives should include smoking cessation, obesity services and exercise programmes. Obesity reduction and exercise are important for long-term risk reduction, but we believe that clinical interventions to control hypertension and atrial fibrillation
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are likely to have greater and more immediate impact. Smoking cessation is just as important. The SE London CCI has a section based on the Quality Markers in the National Stroke Strategy. In the prevention section (QM2: managing risk), the question of whether to use information from ASSET is raised. We believe that ASSET62 has a useful role to enable comparison between PCTs or sectors, including a model quantifying potential numbers of stroke cases prevented, but it has the drawback of using information that is relatively out of date. For that reason, we have not drawn on ASSET data in our report. The SE London CCI also recommends liaison with mental health providers to review CVD risk reduction services for people on severe mental illness registers. We endorse this as part of work to reach hard to reach groups. Initiatives to promote stroke awareness (and the need for prompt admission for acute episodes) are clearly important, and are part of the national stroke strategy. However, neither of the CCI documents has captured the age related issues for stroke prevention – that it is important to prevent strokes in older people as well as in those aged 40 – 74 years in hard to reach and deprived communities. This is not surprising, as it is not yet emphasised in the national stroke strategy or in guidance from Healthcare for London. But it is important for local stroke prevention programmes to include work on older people – see Discussion and Recommendations.

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The toolkit, ASSET (Action on Stroke Services: An Evaluation Toolkit), is an Excel spreadsheet intended to assist NHS commissioners modernise stroke services. It shows PCTs and GPs, by using their own statistics, how better care will save money in the long run, reduce hospital bed days, and save lives. http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuid ance/DH_063260

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7. DISCUSSION
7.1 Demography We have seen how the demography of both SW and SE London is not straightforward. Deprivation is especially profound in parts of SE London, particularly in wards nearest to the centre: in Lambeth, Lewisham and Greenwich. There is also a noticeable area of severe deprivation in North East Bromley. SW London, by contrast, is less deprived in general, although there are pockets of greater deprivation in Wandsworth, Sutton and parts of Croydon. The distribution of people from black and minority ethnic (BME) groups maps quite closely to deprivation, with the highest proportion of BME groups being found nearest the centre of London, especially in SE London. In SW London, there are greater proportions of BME groups in North Croydon and in Merton compared with elsewhere in the SW sector. The geographical distribution of people living over the age of 65 years is fundamentally different from the distributions of both deprivation and BME groups, and maps closely to areas where life expectancy is longest. These areas tend to be more peripheral, and are found in South Croydon, Sutton, Richmond & Twickenham and Kingston (SW London) and in Bromley especially and some parts of Bexley (SE London). The inner city boroughs and PCTs, especially in SE London, are not only the most deprived but show the shortest life expectancies compared with the outer London boroughs. These patterns are essential to appreciate if the pattern of stroke deaths and stroke events is to be understood in both sectors. 7.2 Ethnicity People from BME groups tend to live in the most deprived parts of London. These localities tend to have lowest life expectancy, reflecting the effects of relative poverty in these parts of London. Poverty can be associated with worse access to services, and sometimes is associated with least developed services. All of these factors are associated with poorer general health, including less healthy lifestyles and a greater chance of high individual risk of cardiovascular events.

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There are particular risk factors for stroke to be found in some BME populations. Men of Black African and African-Caribbean origin are known to be at increased risk of hypertension. People of South Asian origin are at increased risk of diabetes. And many men from BME groups have a high prevalence of smoking. All these factors increase the risk of stroke in many BME communities, even before the effects of poverty, deprivation and worse access or contact with services are taken into account. 7.3 Death rates

Death rates at sector level
Stroke death rates have been falling over the years in both SW and SE London, as it has across London as a whole; the rate in SE London has been consistently higher than the London rate, while that in SW London has tended to lie close to the London rate. Stroke death rates in people under 75 have also been falling, but in SE London have been much higher than the London rate, while the rates in younger people in SW London have been lower than the London rate. There is therefore an important health inequality across SE London, where the chances of a stroke death, regardless of age, are higher than elsewhere in the capital – an inequality that is more profound for people under 75 years. Comparing these rates with others across the capital shows what they ought to be – much lower in SE London than they currently are, especially for people under 75 years. These higher rates in SE London correlate with higher deprivation scores, lower life expectancy and larger BME communities. Reducing the risk of stroke death across the whole of SE London, especially in people under 75 years should be a priority area for the SE London sector.

Death rates at PCT level
Within the sectors, the PCTs with the highest stroke death rates across all ages are to be found in SE London – Lambeth, Lewisham, Greenwich and Bexley all have death rates higher than any of the PCTs in SW London. In SW London, PCT death rates are close to the London average apart from Richmond & Twickenham, where the rate is low. The death rate in Bromley (SE London) is even lower. This pattern of death rates correlates to deprivation and reduced life expectancy. For example, Lambeth (highest stroke death rate in the capital) has high deprivation scores, low life expectancy and a large BME community.
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Bromley has low deprivation generally, long life expectancy and fewer people from BME groups. The patterns of death rates for those dying under 75 years are similar but more profound. Lambeth, Lewisham, Greenwich and Southwark (SE London) have high rates; in SW London, death rates in under 75s are average or low in comparison. Again, the PCTs with the highest rates are ones in SE London with the shortest life expectancy and greatest deprivation. These PCTs are Lambeth, Lewisham and Greenwich. 7.4 Addressing inequalities Any community with a higher than average risk of stroke deserves to have this health inequality addressed. In Lambeth and Lewisham, for example, death rates need to be brought down nearer the London average, especially in Lambeth where in people under 75 years it is the highest in the capital. So stroke prevention initiatives are especially important. Effective prevention initiatives will need to be targeted at hard to reach groups, including BME communities where individual stroke risk can often be very high. The numbers of deaths from stroke in these boroughs should be smaller than they are at present. 7.5 Numbers of deaths The relationship between death rates and need and demand for stroke services in London is complex. What is often least understood is that the PCTs with the highest stroke death rates are not the PCTs with the largest numbers of stroke events and stroke deaths across all age groups. The highest numbers of deaths from stroke in SW and SE London occur in those PCTs with the largest populations, the longest life expectancy, the least deprivation and the lowest proportion of people from BME groups. The PCTs concerned are all located towards the periphery of each of sector. This is the same pattern as the one that we have observed in North East London.63 The PCTs with the greatest numbers of stroke deaths are Sutton & Merton, Bromley, Croydon and Bexley – all of whom have death rates around or below the London average. The reason for this pattern is the age profile of these PCTs. There is one main determining feature of death numbers – age.

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Most stroke deaths (nearly 80%) occur in people over the age of 75 years. When numbers of deaths under 75 years are studied, the pattern is different. Most of these deaths occur in the most deprived boroughs with greatest density of BME groups. These boroughs have high death rates overall because of the number of deaths that take place in this younger age group. The striking health inequality experienced by people in these PCTs can be seen in the death numbers for people under 75 years as well as in the rates. We have calculated that across the whole of SE London, a total of 63 less deaths per year would reduce the stroke death rate to that of the London average. Most of these prevented deaths would need to be in people over the age of 75 years. 7.6 Hospital activity The pattern of hospital admissions observed across both sectors (Table 4) relates closely to the pattern of stroke death numbers, since both are related to the size of populations with an older age profile. Most hospital admissions in 2007 occurred to residents of Croydon (SW London) and Bromley (SE London). Our figures were for boroughs rather than PCTs, otherwise Merton & Sutton would have had the highest total of admissions in SW London. Hospital admissions from Lambeth, Lewisham and Greenwich (where death rates – but not numbers - are highest) show lower totals in comparison. These figures show the size of current demand for hospital care across both sectors of South London. The greatest demand for stroke admissions is to be found away from the centre of London. This has important implications for service planning. Currently there is a considerable geographic element in the selection of receiving hospitals caring for acute stroke sufferers in both SW and SE London. In SE London, two thirds of admissions of Bromley residents were to Bromley Hospitals NHS Trust; most of Bexley residents went to Queen Mary Sidcup. In SW London, most residents of Croydon went to Mayday Hospital, while residents of Sutton & Merton went in almost equal numbers to Epsom or St George’s. In SW London rather more patients seem to have been admitted to central London teaching hospitals than from SE London. This probably reflects different arrangements with the London Ambulance Service. The most striking issue from analysing the figures is the greater number of admissions from the outlying PCTs in both sectors (especially Bromley and Sutton & Merton), in comparison with their inner city neighbours.
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Hospital admission rates are low in many PCTs in both sectors, especially in Richmond & Twickenham, Croydon and Bromley. They are much higher than elsewhere in Kingston. The reason for these differences is currently unclear. Many PCTs with high death rates (and probably high event rates) have high admission rates, but there are exceptions such as Lambeth (average admission rates despite very high death rates) and Kingston (average death rates but high admission rates). Admission rates for TIA are strikingly low in all South London PCTs except for Lewisham. The reasons for this pattern should also be explored, as it suggests that many patients having serious TIAs could perhaps be missing out on hospital admission. It is important that admission thresholds should be similar across both sectors. Admission rates for acute stroke may also be affected by admission thresholds and this is an issue which should be explored locally. If admission rates for acute stroke are low because of differentially high admission thresholds, then when thresholds are lowered (once stroke units and hyperacute stroke units are operational, with agreed care pathways across both sectors) then the numbers of admissions per year may increase. This issue is important for demand planning. 7.7 Predicting future patterns of need and demand We have developed a model that can be used to predict stroke prevalence in SW and SE London PCTs between now and 2020. This model shows that if there is no change in smoking and hypertension prevalence, stroke prevalence will increase significantly in all PCTs in both sectors. This is because of projected changes in the age profile of London boroughs over the next 15 years. Age (via the accumulated lifestyle risks that accompany it) is a predominant determinant of stroke risk, which increases markedly after age 65. It will be necessary to reduce hypertension and smoking prevalence to a considerable extent to ameliorate the effects of future ageing on the stroke risks run by people in South London in the future. This finding is very important. It means that stroke prevention initiatives are essential to reduce future burden of stroke and that stroke prevention initiatives must include work to reduce risk in older people. Even then, the demographic changes suggest that strokes are likely to be more common in future years than they are now. This has serious implications for service planning, and especially for estimating the size of future stroke units and the demands to be required of other services, including stroke rehabilitation.

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Our prevalence model does not include the impact of atrial fibrillation (AF). AF is an important risk factor for stroke, especially in older people. Initiatives to detect and treat AF would have a further impact on future stroke prevalence, but this cannot be quantified at present. 7.8 Stroke Prevention A number of stroke risk factors can be diagnosed and controlled, especially hypertension, smoking, obesity / overweight and atrial fibrillation. Local programmes to address these risks are needed. The national Vascular Risk Assessment programme, to be rolled out from April 2009, should, over a period of years, reduce stroke incidence and deaths. This programme has an age limit of 40-74 years. Unfortunately, most strokes occur in people over the age of 75 years. It is therefore essential that local stroke prevention programmes in SW and SE London include initiatives to prevent stroke in people over the age of 75 years. These initiatives need to be targeted at the outer London PCTs with the largest populations of older people – Bromley, Croydon, Sutton & Merton and Kingston – in addition to work identifying cardiovascular risk factors in younger people in hard to reach inner city communities. It is essential to do both. A brief study in three general practices showed that it is feasible to assess stroke risk systematically in people over 75 years. Local programmes to do this in general practice across both sectors should include active case finding for atrial fibrillation. For example blood pressure and pulse rate could be checked in sessions dedicated to flu vaccination in general practice. 7.9 Commissioning Plans We have reviewed the commissioning advice issued to all SW and SE London PCTs in October 2008. Most of this advice relates to the development of better hyper-acute and acute stroke services, and to the commissioning of better stroke rehabilitation services – all of which are outside the scope of this report. The background sections to the commissioning advice documents contain epidemiological data from GP stroke registers which in our view underestimates stroke prevalence by up to 30%. Where hospital admission data is shown, the totals are smaller than the ones we have obtained in this report, probably because of the use of a different range of ICD-10 codes.

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We believe that it is best to use the full range of conditions covered by codes I60-I69. This range will therefore include all varieties of cerebral haemorrhage (including sub-arachnoid haemorrhage) and a few other conditions slightly different from acute thrombotic or embolic stroke. The reason for using this wider range is to understand service need; a more restricted range is likely to lead to underestimates of current and future need for stroke beds and for rehabilitation services. Lastly, the commissioning advice contained little on stroke prevention. It is essential for all PCTs to commission or provide stroke prevention services that are targeted at: • • communities with greatest risk of stroke deaths; communities with large populations of older people, where most stroke events and deaths take place.

It will only be possible to reduce the overall burden of stroke illness in South London if prevention initiatives cover a full range of age groups. The national Vascular Risk Assessment programme, with its age cut-off of 74 years, will not, on its own, significantly reduce the future burden of stroke in SW and SE London until several years have passed. South London PCTs should consider commissioning locally enhanced service contracts with general practice teams to ensure delivery of programmes that systematically assess and address stroke risk in people aged 75 years and above.

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8. RECOMMENDATIONS
10. The SW and SE London Cardiac and Stroke Network Boards should continue to monitor stroke death rates and death numbers across all PCTs in each sector, using robust and standard sources of public health information. A wide variation in hospital admission rates for stroke has been observed across PCTs in both SW and SE London. The reasons for this are unclear, but it is possible that some low rates could be partly due to high admission thresholds. Events involving local clinicians (to explore care pathways and referral problems) would probably be helpful in all PCTs but especially those with low rates, such as Croydon, Richmond & Twickenham (SW), Bromley and Bexley (SE). Low rates of admission for TIA are very striking across both sectors (except in Lewisham) and should similarly be investigated. Both Boards should advocate stroke prevention initiatives for people under the age of 75 years, in line with the national Vascular Risk Assessment (VRA) Programme. This should be implemented by all PCTs, but especially those with particularly high death rates and numbers in this age group – Lambeth, Lewisham and Greenwich (SE). This work should involve targeted initiatives in areas of deprivation, black and minority ethnic communities and groups that may be hard to reach. Stroke prevention programmes should also include specific interventions to reduce stroke risk in the age group in which most stroke events occur – those over the age of 75 years. This is a priority for all PCTs in both sectors, but especially for those with particularly high burdens of stroke illness: Sutton & Merton and Croydon (SW); Bromley and Bexley (SE). All stroke prevention programmes should emphasise the impact of diagnosis and effective management of hypertension and atrial fibrillation across all age groups, and of smoking cessation (as well as other stroke risk factors such as abnormal lipid profiles and obesity). Case finding for hypertension and atrial fibrillation is a particular priority. Both Network Boards should consider commissioning work to model in detail the future demand for hospital admissions for stroke between now and 2020, assuming clinical care pathways are optimised, and taking into account future stroke prevalence under different prevention scenarios.
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11.

12. 13.

14.

15.

16.

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17.

This need to model future demand for stroke services should be raised by both Boards in discussion with Healthcare for London – to ensure that the modelling is robust, transparent and able to inform capacity planning for South London. Future commissioning guidance for PCTs across both sectors should draw on robust public health information. It should contain detailed advice on stroke prevention, incorporating not only the VRA programme, but also the need to screen people over 75 years of age for risk factors such as hypertension and atrial fibrillation – perhaps through the use of Local Enhanced Service contracts with general practice teams.

18.

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Annex: Stroke Prevalence Preventions Scenarios, South London PCTs / Sectors

Numbers of prevalent cases of stroke

Numbers of prevalent cases of stroke

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Numbers of prevalent cases of stroke

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Numbers of prevalent cases of stroke

Numbers of prevalent cases of stroke

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Numbers of prevalent cases of stroke

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Numbers of prevalent cases of stroke
30000

Stroke prevalence prevention scenarios: SE Sector
29000

Numbers of prevalent cases of stroke

28000 e k o r 27000 t s f o s e 26000 s a c t n e l 25000 a v e r p f 24000 o s r e b 23000 m u N 22000 21000 20000 2006 2010 2015 2020

No change Scenario 1- hypertension 3% decrease/5 years Scenario 2- hypertension 6% decrease/5 years

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Percent

Numbers of prevalent cases of stroke

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Percent

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