US Physicians Health Study - Physicians Health Study


Aspirin versus placebo for primary prevention of cardiovascular disease.


To determine if low-dose aspirin is associated with a reduction in cardiovascular mortality.

Study Design

Study Design:

Patients Screened: Not reported
Patients Enrolled: 22,071
NYHA Class: Not reported
Mean Follow Up: Average 5 years (range 45.8 to 77.0 months)
Mean Patient Age: 40-84
Female: 0%
Mean Ejection Fraction: Not evaluated

Patient Populations:

Male physicians 40–84 years of age.

Primary Endpoints:

Cardiovascular mortality

Secondary Endpoints:

Nonfatal MI, stroke, sudden death, other ischemic heart disease, all-cause mortality

Drug/Procedures Used:

Aspirin 325 mg every other day or placebo. 5.7% requested an enteric coated preparation.

Principal Findings:

The aspirin group had a 44% reduction in the incidence of MI (0.255%/yr vs. 0.44%/yr, p < 0.00001). Of note, this benefit was restricted to individuals >50 years of age. The aspirin group had a nonsignificant reduction in cardiovascular mortality (0.73% vs 0.75%, RR 0.96, p=0.87). There was no significant difference between the groups in all stroke events (RR 1.22, p=0.15). However, there was a trend toward more hemorrhagic strokes in aspirin group (RR 2.1; p = 0.06); this subgroup included 13 moderate-to-severe or fatal strokes in the aspirin group and 6 in the placebo group. In the 333 patients with chronic stable angina, the risk of MI was decreased by an impressive 87%. Aspirin use was associated with a higher incidence of peptic ulcers (0.35% vs 0.2%, RR 1.77, p=0.04)


This study was stopped early because of the conclusive reduction in the risk of nonfatal MI but the evidence regarding stroke and total cardiovascular deaths is inconclusive because of the very low event rates.


N Engl J Med 1989;321:129–135.Primary report. Ann Intern Med 1991;114:875. Stable angina population.

Keywords: Coronary Artery Disease, Stroke, Platelet Aggregation Inhibitors, Angina, Stable, Peptic Ulcer, Primary Prevention

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