Estimating CHD prevalence by small area: integrating information from health surveys and area mortality.

The risk of coronary heart disease (CHD) is strongly linked both to deprivation and ethnicity and so prevalence will vary considerably between areas. Variations in prevalence are important in assessing health care needs and how far CHD service provision and surgical intervention rates match need. This paper uses a regression model of prevalence rates by age, sex, region and ethnicity from the 1999 and 2003 Health Surveys for England to estimate CHD prevalence for 354 English local authority areas. To allow for the impact of social factors on prevalence, survey information on the deprivation quintile in the respondents' micro-area of residence is also used. Allowance is also made for area CHD mortality rates (obtained from aggregated vital statistics data) which are positively correlated with, and hence a proxy for, CHD prevalence rates. An application involves assessment of surgical intervention rates in relation to prevalence at the level of 28 Strategic Health Authorities.