Prepared by:

Tracy Wolff, MD, MPH

Therese Miller, DrPH

Stephen Ko, MD, MPH

Agency for Healthcare Research and Quality

U.S. Department of Health and Human Services

540 Gaither Road

Rockville, Maryland 20850

AHRQ Publication No. 09-05129-EF-1

March 2009

This report is based on research conducted by staff of the Agency for Healthcare Research and Quality (AHRQ), Rockville, MD. The investigators involved have declared no conflicts of interest with objectively conducting this research. The findings and conclusions in this document are those of the authors, who are responsible for its content, and do not necessarily represent the views of AHRQ. No statement in this report should be construed as an official position of AHRQ or of the U.S. Department of Health and Human Services.

The information in this report is intended to help clinicians, employers, policymakers, and others make informed decisions about the provision of health care services. This report is intended as a reference and not as a substitute for clinical judgment.

This report may be used, in whole or in part, as the basis for the development of clinical practice guidelines and other quality enhancement tools, or as a basis for reimbursement and coverage policies. AHRQ or U.S. Department of Health and Human Services endorsement of such derivative products may not be stated or implied.

A version of this report was published in Annals of Internal Medicine on March 17, 2009.

Suggested AHRQ Citation: Wolff T, Miller T., Ko S. Aspirin for the Primary Prevention of Cardiovascular Events: An Update of the Evidence for the U.S. Preventive Services Task Force. Evidence Synthesis No. 68. AHRQ Publication No. 09-05129-EF-1. Rockville, Maryland: Agency for Healthcare Research and Quality, March 2009.