Aspirin prophylaxis in patients at low risk for cardiovascular disease: A systematic review of all-cause mortality

OBJECTIVE We investigated whether aspirin reduces all-cause mortality in low-risk patients. STUDY DESIGN We systematically reviewed studies of aspirin for primary prevention to measure total mortality. We included all clinical trials, cohort studies, and case control studies that assessed primary prevention, included low-risk subjects, and measured total mortality. The quality of studies was evaluated with a standard scale. DATA SOURCES MEDLINE, the Cochrane Library, and the Internet were systematically searched for studies with the key terms primary, prevention, aspirin, myocardial infarction, stroke, and mortality. Reference lists of identified trials and reviews also were examined. POPULATION Active members in the Indiana Academy of Family Physicians 2000-2001 membership database (N = 1328). OUTCOMES MEASURED Primary outcomes were myocardial infarction, stroke, and mortality. RESULTS Three primary prevention studies met our criteria. Two clinical trials, the United States Physicians Health Study and British Doctors Study, demonstrated no significant decrease in mortality in the aspirin group alone or when results from the 2 studies were combined. The United States Physicians Health Study showed a lower rate of myocardial infarction (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.47-0.71). In the Nurses Health Study, a cohort study, taking aspirin at any close was associated with higher rates of myocardial infarction (OR, 2.34; CI, 1.92-2.86), stroke (OR, 1.84; CI, 1.39-2.44), and all-cause mortality (OR, 1.83; CI, 1.57-2.14). CONCLUSIONS There is currently no evidence to recommend for or against the use of aspirin to decrease mortality in low-risk individuals.