Observational Aspirin Use and CVD in the Physicians' Health Study

To analyze existing data from the Physicians Health Study (PHS), a randomized primary prevention trial of low-dose aspirin and beta carotene conducted among 22,071 U.S. male physicians, to address questions concerning aspirin and cardiovascular (CV) disease that could not adequately be addressed during the randomized aspirin period.

Study Overview

Detailed Description

DESIGN NARRATIVE:

The aspirin component of the trial was terminated on January 25, 1988, due to a demonstrated benefit of aspirin on myocardial infarction. At that time, however, the number of strokes and CV deaths experienced by trial participants was inadequate to definitively evaluate these endpoints. The beta carotene component of the trial continued uninterrupted until its scheduled termination in December, 1996. During this period detailed information continued to be collected on post-trial aspirin use through annual questionnaires. As of October, 1995, the number of deaths, including cardiovascular deaths, had increased fourfold from that in the randomized period, and the number of strokes had increased 3.5 times. The investigators used data from both the randomized aspirin period and the observational period following the trial to assess the impact of aspirin use on cardiovascular and total mortality, and the long-term impact of aspirin use on subsequent stroke and MI. The methods included analyses of both randomized aspirin assignment and of time-varying aspirin use, as assessed on the annual questionnaires. Because of the potential for bias, the propensity for aspirin use, particularly during the observational period was taken into account. Analyses included use of proportional hazards models allowing for both time-varying effects of aspirin use and controlling for time-varying confounders, as well as more complex procedures using causal modeling.

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.

Investigators

  • Nancy Cook, Brigham and Women's Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

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

April 1, 1998

Study Completion (Actual)

March 1, 2001

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

August 1, 2004

More Information

Terms related to this study

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.

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