Compliance in the Physicians' Health Study

To evaluate the relationships of compliance in taking aspirin or aspirin placebo with the risk of major cardiovascular endpoints, using data collected in the Physicians' Health Study.

Study Overview

Detailed Description

BACKGROUND:

The Physicians' Health Study was a randomized, double-blind placebo-controlled primary prevention trial designed to test whether 325 mg aspirin every other day reduced risks of cardiovascular disease and whether 50 mg beta-carotene on alternate days decreased cancer incidence among 22,071 male U.S. physicians, aged 40-84 years in 1982. Compliance with study pills, the use of non-study aspirin and platelet active drugs, specific side effects of aspirin, the incidence of conditions indicating aspirin use, and study outcomes were assessed at six month intervals during the first year and annually thereafter. The blinded aspirin component of the trial was terminated early and participants were unblinded on January 25, 1988, due to the emergence of a statistically extreme benefit of aspirin on both fatal and nonfatal myocardial infarction, as well as the extraordinarily low cardiovascular mortality rates among study participants.

DESIGN NARRATIVE:

Separate dose-response relationships were estimated in the aspirin and in the placebo group to determine whether compliance in the placebo group was associated with lower risk, as had been found in some previous trials. Rates of cardiovascular endpoints in the placebo group relative to the aspirin group were adjusted for time-varying compliance with study tablets, and the use of non-study aspirin and platelet active drugs. In addition, baseline characteristics of the population and longitudinal assessment of side-effects and new conditions suggesting aspirin therapy were used as predictors of compliance in taking study pills separately in the aspirin and placebo groups. Similar longitudinal analyses determined predictors of the use of non-study aspirin and platelet active drugs. The analyses were intended to supplement the already published intent-to-treat analyses. They provided observational evidence concerning dose of aspirin and the risks of major cardiovascular endpoints. Examining modification of the aspirin effect in reducing risk of myocardial infarction according to level of compliance aided in the generalizability of results to less motivated populations. Evaluating determinants of good study compliance should be of benefit to future large scale clinical trials.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Study Type

Observational

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

No older than 100 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

No eligibility criteria

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

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Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 1991

Study Completion (Actual)

January 1, 1993

Study Registration Dates

First Submitted

May 25, 2000

First Submitted That Met QC Criteria

May 25, 2000

First Posted (Estimate)

May 26, 2000

Study Record Updates

Last Update Posted (Estimate)

March 16, 2016

Last Update Submitted That Met QC Criteria

March 15, 2016

Last Verified

May 1, 2000

More Information

Terms related to this study

Other Study ID Numbers

  • 4321
  • R03HL046163 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Myocardial Infarction

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