Prevalence of angina in women versus men: a systematic review and meta-analysis of international variations across 31 countries.

BACKGROUND In the absence of previous international comparisons, we sought to systematically evaluate, across time and participant age, the sex ratio in angina prevalence in countries that differ widely in the rate of mortality due to myocardial infarction. METHODS AND RESULTS We searched MEDLINE and EMBASE until February 2006 for healthy population studies published in any language that reported the prevalence of angina (Rose questionnaire) in women and men. We obtained myocardial infarction mortality rates from the World Health Organization. A total of 74 reports of 13,331 angina cases in women and 11,511 cases in men from 31 countries were included. Angina prevalence varied widely across populations, from 0.73% to 14.4% (population weighted mean 6.7%) in women and from 0.76% to 15.1% (population weighted mean 5.7%) in men, and was strongly correlated within populations between the sexes (r=0.80, P<0.0001). Angina prevalence showed a small female excess with a pooled random-effects sex ratio of 1.20 (95% CI 1.14 to 1.28, P<0.0001). This female excess was found across countries with widely differing myocardial infarction mortality rates in women (interquartile range 12.7 to 126.5 per 100,000), was particularly high in the American studies (1.40, 95% CI 1.28 to 1.52), and was higher among nonwhite ethnic groups than among whites. This sex ratio did not differ significantly by participant's age, the year the survey began, or the sex ratio for mortality due to myocardial infarction. CONCLUSIONS Over time and at different ages, independent of diagnostic and treatment practices, women have a similar or slightly higher prevalence of angina than men across countries with widely differing myocardial infarction mortality rates.