1

Aims of Presentation

• “Uses of Health Examination Survey in England” – Health Survey for England (HSfE)

+

• Why England incorporated an examination component in HSfE

2

Perspectives

• Personal• Medical epidemiologist• Public health doctor

• Organisational• Department of Health (England)• Health monitoring unit• Policy directorate (public health)

3

Current review of Survey Programme

The Health Survey for England has been commissioned by the Information Centre for health and social care (IC) since April 2005; and carried out since 1994 by the Joint Health Surveys Unit.

• The IC is currently undertaking a review of the entire survey programme.

4

Early history - context

• Late 1980s• Chief Medical Officer• Health strategy

• Identify key issues• Targets

• Health survey• Fact finding in USA

5

Why a health survey? [1]

• Information needed for all stages of policy making process:

• Strategy development• Policy initiation• Option appraisal• Development• Implementation• Monitoring• Evaluation• Review

6

Why a health survey? [2]

Good information on various aspects:

• Mortality data

• Cancer incidence and survival

• Information on use of services:– secondary care (good)– primary care (limited)

• Self-reported behaviour (risk factors)

7

Why a health survey? [3]

• Other surveys– Specific eg diet and nutrition– Health questions in general household

surveys• Research studies – eg Whitehall studies of

civil servants; British Regional Heart Study

>>>>>>>>>>>>>>>>>>>>>>>>>• But insufficient for supporting a health

strategy

8

Why a health examination survey?

Only limited information on objective measures of health and risk factors

+Distribution in the population

• age• gender• socio-economic measures• ethnicity

9

Issues

Cost• Finance• Opportunity costs

Political factors• Priorities• Identifying undetected or untreated disease

Initial focus

10

Issues (2)

Sample size

Geographical coverage

Topic coverage

One stage or two stage

Trained interviewers vs Nurses

Effects on response rates

11

The Health Survey for England (HSfE) – early years

• Annual survey about the health of people in England. • First proposed in 1990 to improve information of

morbidity and determinants of health. • Information for use in underpinning and improved

targeting of nationwide health policies.• The survey was carried out in 1991-1993 by the Office

for Population Censuses and Surveys which is now part of the Office for National Statistics.

• From 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.

12

HSfE – initial aims

• to provide annual data about the nation's health; • to estimate the proportion of the population with specific

health conditions; • to estimate the prevalence of risk factors associated

with those conditions; • to assess the frequency with which combinations of risk

factors occur; • to examine differences between population sub-

groups; • to monitor targets in the health strategy; • (from 1995) to measure the height of children at different ages,

replacing the national study of health and growth.

13

The Health Survey for England (HSfE) – 1991-93

• Cardiovascular focus• Initial limited sample size• Adults

*******************************************************• Addressed key priorities – supported Health of

the Nation strategy (including 2 targets)

14

'Core' topics

• general health • smoking and drinking behaviour • blood pressure • height and weight • other anthropometric measures • prescribed medication • fruit and vegetable consumption (since

2002)

15

Why continue the HSfE

• Ongoing need for monitoring trends• New policy priorities (see next slide)

• Frequency of assessment

• Stop/start process logistically unhelpful

• Added value of new data– Monitoring– Amalgamating years for more local data

16

The agenda evolves

Non-Core' topics (1)• cardiovascular disease (1991-94, 1998, 2003) • asthma + other respiratory diseases (1995-97) • lung function (1995-97) • atopic conditions (1995-96) • eating habits (1993-94, 1997) • physical activity (1991-94, 1997) • accidents (1995-97)

17

The agenda evolves

Non-Core' topics (2)• General Health Questionnaire (1991-95, 1997) • generic health state measures EuroQol and SF-36 (1996)

• disability (1995) • contraceptive use (1992-95, 1997)

• ethnic minority health (1999, 2004)

• older people - including care home residents (2000) • fruit and vegetable consumption (2001)

• children, young people, and maternal health (2002)

18

Examination components

• Aside from core variables, measurements vary year on year, eg:

• Blood samples (eg glycosylated Hb, ferritin, gamma GT, cholesterol, fibrinogen, serum cotinine, IgE, house dust mite IgE, lead, c-reactive protein, triglycerides, glucose,)

• Spot urine samples• Salivary cotinine• Lung function tests• Grip strength/balance [older persons]

19

Monitoring & Reporting

20

HSfE – Parliamentary Questions

Cholesterol• Rosie Cooper: To ask the Secretary of State for Health what

estimate she has made of the percentage of adults in West Lancashire with high cholesterol levels. [64112]

• Mr. Byrne: The information is not available in the format requested. Data on cholesterol levels are available from the Health Survey for England (HSE). The most recent data available on cholesterol are for 2003, as this is the last year where the HSE focused on cardiovascular disease.

• The results in the table show the mean total cholesterol levels for adults for England and the North West Government Office Region, broken down by gender for 2003.

21

HSfE - Source for national & international databases

• The WHO Global InfoBase is a data warehouse that collects, stores and displays information on chronic diseases and their risk factors for all WHO member states

• Blood Pressure: Raised blood pressure causes stroke and heart disease

• Cholesterol: High cholesterol levels increase the risk of coronary heart disease

• Overweight & Obesity: (BMI)

22

National Service Frameworks

National service frameworks (NSFs) are long term strategies for improving specific areas of care. They set national standards, identify key interventions and put in place agreed time scales for implementation– Blood pressure– Cancer– Children– Coronary heart disease– Diabetes– Long term conditions– Long term neurological conditions– Mental health– Renal

Health examination data feeds into development and monitoring of these NSFs.

23

HSfE- health inequalities

24

HSfE- health inequalities

25

Health Inequalities

Health Survey for England reports on data by:

• Age• Gender• Area (including “Spearhead” areas)• Equivalised household income• [Social class/NS-SEC]• [Ethnicity]

26

Targets

Target setting – eg Health of the Nation, Our Healthier Nation

+Target monitoring:

BMJ 1996 (8 June) News

• Britain is failing to meet targets on reducing obesity • 17% of men (19% of women) had a systolic blood pressure over 160 mm Hg or

were being treated for hypertension. • A drop in the average systolic blood pressure from 139 mm Hg to 136 mm Hg

was found in 16 to 64 year olds. These figures suggest a downward trend towards the government's target of an average systolic pressure of 133 mm Hg by the year 2005.

• But future surveys are needed to see whether the trend will continue.

27

Driver for action

Improved hypertension and management and control: Results From the Health Survey for England 1998, Primatesta et al

28

CMO recommendations

29

CMO recommendations (2)

30

Quantifying impacts

31

Quantifying impact of interventions

CHD: Estimating the impact of changes in risk factors(McPherson Klim, Britton Annie, Causer Louise)

main risk factors for CHD: cholesterol, physical activity, blood pressure, smoking and obesity

estimates the relative impact that changes to these risk factors may have on the number of cases and deaths from the disease in England.

each risk factor is looked at individually and the percentage reduction in coronary heart disease that could be achieved in the population as a whole, and where possible, among individual groups is assessed

32

Planning for the future

33

Health Poverty Index

34

HPI – “health capital”

Individuals potential for health across the life course

• Need to provide small area estimates• Modelled estimates produced:

– Obesity – Blood pressure – Cholesterol – Low birth weight (for infants)

35

Prevalence modelling

Models that show the expected prevalence of disease in given geographies and user-defined populations

Hypertension Coronary Heart DiseaseDiabetesChronic Obstructive Pulmonary DiseaseChronic Kidney Disease

36

Prevalence modelling (2)

• Disease prevalence models to support 2007-8 Primary Care Trust (PCT) “Local Delivery Plans (LDPs)”

• Association of Public Health Observatories was commissioned by the DH to produce PCT level prevalence estimates for hypertension and coronary heart disease. These estimates are based on two separate models derived from the Health Survey for England (HSE).

• Models are only intended to give indicative expected prevalence and are part of ongoing work to produce refined estimates.

• Comparisons of national prevalence data from the HSE and

recorded prevalence from the Quality and Outcomes Framework (QOF) suggest that there is considerable under-diagnosis (in terms of IT system recording) of risk factors and diseases.

37

Prevalence modelling – COPD (1)

• The overall prevalence of COPD in England is estimated as 1.3 million, of whom as many as 600,000 people may be unaware of their diagnosis, therefore missing the opportunity of benefiting from early interventions.

• importance of active case finding • model can be used to identify areas with a high level of unmet

needs, i.e. with a high proportion of undiagnosed disease, where the benefits of case finding would be optimised.

• This strategy may also have an impact on reducing health inequalities, due to the socio-economic class gradient in COPD prevalence.

• The model should be validated, and case-finding strategies using the model should be evaluated for their cost-effectiveness.

[Luis C Nacul, Michael Soljak, and Tom Meade September 2007]

38

Prevalence modelling – COPD (2)

• A mathematical model based on HSfE developed• Logistic regression analysis was used to investigate and

choose risk factors for inclusion in the model and to derive the prevalence estimates based on the strength of association between selected risk factors and the outcome COPD.

• The model allows the prevalence to be estimated in populations at national level and also at regional and large local areas, based on their compositions according to age, sex, smoking and ethnicity, and on area degrees of urbanisation and deprivation.

39

Prevalence modelling – COPD (3)

A main advantage of the HSfE model is that it is:– based on high quality data – from a large representative sample of the population,

and,– uses standard and specific diagnostic criteria for

COPD, – which is based on lung function rather than symptoms.

40

Prevalence modelling – COPD (4)

• estimated the overall prevalence of COPD in England as 3.1% in people over 15 years old and 5.3% in those over 45 years old.

• model illustrates the huge inequalities in the prevalence of COPD across England (extreme risks in black men in urban deprived areas in one end of the risk spectrum, and Asian women in the lowest deprived rural areas, in the opposite end, between whom the risk of

COPD varies 7-fold on average) • Thus simpler models that do not take into account such

variations in prevalence across population groups, would be inappropriate for local use.

41

Prevalence modelling – COPD (5)

• “We believe that compared to previous models and prevalence estimates, the HSfE-Model offers the most reliable estimates for England and the United Kingdom.

• It recognises deprivation, urban living and ethnicity as independent risk factors for COPD, which are taken into account in the estimates derived, in addition to smoking, age and gender.

• The model gives prevalence estimates for areas of varying sizes, including large populations at local level, however, the precision of the estimates will be higher for larger areas.”

[Luis C Nacul, Michael Soljak, and Tom Meade September 2007]

42

HSfE- other uses: eg

• Project: Ethnic differences in hypertension, diabetes, dyslipidemia and the role of contextual factors: A comparative analysis between the Netherlands (the SUNSET study), and the UK studies (the Newcastle Heart Study and Health Survey for England)

• Cardiovascular disease (CVD) is a major public health burden and the rates are higher in some minority populations than in White populations. The causes of the excess risks are incompletely understood and pose a high level scientific challenge. International comparisons provide a good opportunity to gain more insight into the role of contextual factors (i.e. lifestyle, health care and socio-economic factors) in ethnic disparities in health.

43

HSfE- other uses

44

HSfE- examples of uses (1)

• Descriptive– Monitoring (general)/Surveillance– National/international collations/databases– Targets

• Health inequalities• CMO report – highlighting issues• Underpinning policy development National

Service Frameworks –

45

HSfE- examples of uses (2)

• Health Poverty Index – modelled variables

• National prevalence models– All– COPD

• Risk factor models

• Future scenarios

• Research

46

Final reflections (1)

“In England and Wales, the CHD NSF, NHS Plan, and CHD Information Strategy now explicitly recognise the huge importance of disease Monitoring and service evaluation. All have made a number of specific and sensible recommendations. However, at present over 99% of the £2 billion NHS CHD budget is spent on medical interventions, particularly revascularisation. Less than 1% is currently spent on the monitoring of CHD. These are inadequate resources for evenbasic information strategy or information technology.”

47

Final reflections (2)

• Examination component gives us critical information on key aspects of health status and health determinants

• The examination component may be considered a relatively expensive component of the survey programme but it is essential for informed (“evidence-based”) policy-making

48

Final reflections (3)

• Major hurdle: getting programme started• Monitoring tool

– Frequency of surveys [1y;2y;5y] – monitoring and practical issues– Timeliness of data (headline figures)

• Costs & opportunity costs• Added value of combining information• Relevance – eg to political agenda• Evolution vs ongoing monitoring• Standardised measurements vs GP systems• Local perspective• EU information