Regional variation in incidence and case fatality of myocardial infarction among young women in England, Scotland and Wales

OBJECTIVES: To examine the regional variation in incidence and case fatality of myocardial infarction among young women. DESIGN: Cross sectional survey, using population based incidence data. SETTING: England, Scotland and Wales. SUBJECTS: Subjects were women aged 16-44 with a diagnosis of myocardial infarction between 1 October 1993 and 15 October 1995. OUTCOME MEASURES: Incidence of myocardial infarction per 100,000 women years, with case fatality as a percentage of total cases. RESULTS: Incidence of myocardial infarction rose steeply from age 33 upwards, (maximum = 20.2 cases per 100,000 women years at age 44). The adjusted incidence rate for myocardial infarction was 3.7 (95% CI 3.2, 4.2) times greater in Scotland than in southern England. In contrast, case fatality was significantly lower in Scotland: 18.5% (95% CI 13.1%, 25.0%), compared with 31.0% (95% CI 25.9%, 36.0%) in southern England. CONCLUSIONS: The incidence of myocardial infarction varied widely within the United Kingdom. Case fatality variation may reflect differences in ambulance response, or in diagnostic acumen, within the regions.