Randomised trial of prophylactic daily aspirin in British male doctors

TLDR

A six‑year randomized trial of 5,139 healthy male doctors assigned to 500 mg daily aspirin versus no aspirin evaluated its effect on incidence and mortality of stroke, myocardial infarction, and other vascular events. Over six years, 5,139 healthy male doctors randomized to 500 mg daily aspirin showed a non‑significant 10 % lower total mortality, no significant reduction in non‑fatal myocardial infarction or stroke (disabling strokes were slightly more common), a 25 % upper bound on potential benefit, and reduced reports of migraine and musculoskeletal pain, but no effect on cataract incidence or vascular death, underscoring that aspirin’s preventive value in primary prevention remains uncertain.

Abstract

A six year randomised trial was conducted among 5139 apparently healthy male doctors to see whether 500 mg aspirin daily would reduce the incidence of and mortality from stroke, myocardial infarction, or other vascular conditions. Though total mortality was 10% lower in the treated than control group, this difference was not statistically significant and chiefly involved diseases other than stroke or myocardial infarction. Likewise, there was no significant difference in the incidence of non-fatal myocardial infarction or stroke—indeed, disabling strokes were somewhat commoner among those allocated aspirin. The lower confidence limit for the effect of aspirin on non-fatal stroke or myocardial infarction, however, was a substantial 25% reduction. Migraine and certain types of musculoskeletal pain were reported significantly less often in the treated than control group, but as the control group was not given a placebo the relevance of these findings was difficult to assess. There was no apparent reduction in the incidence of cataract in the treated group. The lack of any apparent reduction in disabling stroke or vascular death contrasts with the established value of antiplatelet treatment after occlusive vascular disease.