Geographical variation in cardiovascular disease, risk factors, and their control in older women: British Women's Heart and Health Study

Objectives: To measure the geographical variation in prevalence of cardiovascular disease, risk factors, and their control in a nationally representative sample of older British women. Methods: Baseline survey using general practitioner record review, a self completed questionnaire, research nurse interview, and physical examination in a randomly selected sample of women aged 60-79 drawn from 23 towns in England, Scotland, and Wales. Results: Of 7173 women invited and eligible to participate, information was obtained on 4286 (60%). One in five women had a doctor diagnosis of any one of myocardial infarction, angina, heart failure, stroke, or peripheral vascular disease. Fifty per cent of women were hypertensive, 12% smoked, and over one quarter were obese. Fifty per cent had a total cholesterol level greater than 6.5 mmol/l, though only 3% had low high density lipoprotein concentrations. Cardiovascular disease prevalence varied by geographical region being highest in Scotland: age adjusted prevalence (95% confidence intervals) 25.0% (21.5% to 28.8%) and lowest in South England: age adjusted prevalence (95% confidence intervals) 15.4% (13.5% to 17.6%). The geographical variations in cardiovascular disease prevalence were attenuated by adjustment for risk factors and socioeconomic position; further adjustment for health service use (as indicated by aspirin or statin use) reduced the differences further. However, variation remained even after full adjustment for these factors: odds ratio (95% confidence intervals) comparing Midlands and Wales to South England 1.15 (0.82 to 1.61) and comparing Scotland to South England 1.53 (1.08 to 2.14). Of women with cardiovascular disease, 12% were current smokers, a third had uncontrolled hypertension, a third were obese, and 90% had a blood cholesterol over 5 mmol/l. Only 41% were taking antiplatelet drugs and 22% were taking a statin. Conclusions: Older British women have a higher prevalence of cardiovascular disease and risk factors than previously documented. The workload consequences of attempting to control risk factors and ensure optimal secondary prevention for older British women are considerable. Geographical variations in cardiovascular disease prevalence in older women are somewhat, but not fully, explained by variations in major risk factors, socioeconomic position, and health service utilisation.