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Physicians' Health Study

This study has been completed.
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
John Michael Gaziano, MD, Brigham and Women's Hospital Identifier:
First received: October 27, 1999
Last updated: January 24, 2014
Last verified: January 2014
To assess the effect on cardiovascular mortality of alternate-day consumption of 325 milligrams of aspirin and, secondarily, the effect on cancer incidence of alternate-day consumption of 50 milligrams of beta-carotene.

Condition Intervention Phase
Cardiovascular Diseases
Coronary Disease
Heart Diseases
Myocardial Ischemia
Drug: aspirin
Drug: carotene
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Masking: Double-Blind
Primary Purpose: Prevention

Further study details as provided by Brigham and Women's Hospital:

Study Start Date: September 1981
Study Completion Date: December 1996
Primary Completion Date: December 1995 (Final data collection date for primary outcome measure)
Detailed Description:


Thrombosis plays a major role in the late stages of coronary occlusion. Platelet aggregation is a large component in the formation of arterial thrombi. In pharmacologic studies, aspirin has been shown to inhibit platelet aggregation and, therefore, might be expected to prevent coronary occlusion. These effects are apparent in the dose range of l00-l000 mg/day, and may be most evident at l60 milligrams daily. Higher doses seem to be no more effective in either inhibition of platelet agreeability or prolonged bleeding time.

Although an early case-control study by Jick and Miettinen showed a large benefit, most observational studies had shown a cardiovascular benefit of about 20 percent. Conclusive data could only result from a randomized trial with a large sample size.


Randomized, double-blind, fixed sample. Participants were randomized into one of four treatment groups: one 325 milligram aspirin tablet every other day, alternating with one 30 milligram capsule of beta-carotene; one aspirin every other day, alternating with one capsule of beta-carotene placebo; one aspirin placebo tablet every other day, alternating with one capsule of beta-carotene; and one aspirin placebo tablet every other day, alternating with one capsule of beta-carotene placebo. Major endpoints for the cardiovascular component of the study were cardiovascular mortality, total mortality, and coronary events.


Ages Eligible for Study:   40 Years to 84 Years   (Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Male physicians, ages 40 to 84. No history of stroke, myocardial infarction, cancer, or renal disease. No contraindications to aspirin or beta-carotene. No current usage of aspirin or Vitamin A tables greater than once per week.
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  More Information


Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: John Michael Gaziano, MD, Chief, Division of Aging, Brigham and Women's Hospital Identifier: NCT00000500     History of Changes
Other Study ID Numbers: 19
R01HL034595 ( US NIH Grant/Contract Award Number )
Study First Received: October 27, 1999
Last Updated: January 24, 2014

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Coronary Disease
Coronary Artery Disease
Myocardial Ischemia
Pathologic Processes
Vascular Diseases
Arterial Occlusive Diseases
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs processed this record on May 25, 2017