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Physicians' Health Study

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: October 28, 1999
Last Update Posted: March 17, 2014
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
John Michael Gaziano, MD, Brigham and Women's Hospital
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
Primary Purpose: Prevention

Further study details as provided by John Michael Gaziano, MD, 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.


Information from the National Library of Medicine

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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.
  Contacts and Locations
No Contacts or Locations Provided
  More Information


Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: John Michael Gaziano, MD, Chief, Division of Aging, Brigham and Women's Hospital
ClinicalTrials.gov Identifier: NCT00000500     History of Changes
Other Study ID Numbers: 19
R01HL034595 ( U.S. NIH Grant/Contract )
First Submitted: October 27, 1999
First Posted: October 28, 1999
Last Update Posted: March 17, 2014
Last Verified: January 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