Geographical variation in cardiovascular incidence: results from the British Women's Heart and Health Study

Seven-year follow-up data on 2685 women aged 59-80 (mean 69) at baseline from 23 towns in the UK were available from the British Women's Heart and Health Study. Time to fatal or non-fatal CVD was analyzed using Cox regression with adjustment for risk factors, using multiple imputation for missing values.Compared to South England, CVD incidence is similar in North England (HR 1.05 (95% CI 0.84, 1.31)) and Scotland (0.93 (0.68, 1.27)), but lower in Midlands/Wales (0.85 (0.64, 1.12)). Event severity influenced regional variation, with South England showing lower fatal incident CVD than other regions, but higher non-fatal incident CVD. Kaplan-Meier plots suggested that regional divergence in CVD occurred before baseline (before mean baseline age of 69).In women, regional differences in CVD early in adult life do not further diverge in later life. This may be due to regional differences in early detection, survivorship of women entering the study, or event severity. Targeting health care resources for CVD by geographic variation may not be appropriate for older age-groups.Geographical variations in coronary heart disease (CHD) and stroke (together termed cardiovascular disease (CVD) here) have been identified and reported for a range of countries in terms of both prevalence [1-16] and incidence [17-21]. Furthermore, a number of studies have investigated the relationship between geographical variation in these outcomes and known risk factors [11,17,18,22-24]. The British Regional Heart Study (BRHS) reported that the north-south differences in CVD incidence in men could largely be explained by classical risk factors (smoking, physical activity, body mass index (BMI), alcohol consumption, systolic blood pressure, serum total cholesterol, occupational social class, and height) [18]. In women, differences in CVD prevalence across four broad regions of the UK (Scotland, North England, Midlands/Wales, and South England) were reported at the baseline survey of the British Women'