Prepared for:

Agency for Healthcare Research and Quality

U.S. Department of Health and Human Services

540 Gaither Road

Rockville, MD 20850

www.ahrq.gov

Contract No. 290-02-0024

Task Order No. 2

Technical Support of the U.S. Preventive Services Task Force

Prepared by:

Oregon Evidence-based Practice Center

Portland, Oregon

Roger Chou, MD

P. Todd Korthuis, MD, MPH

Laurie Hoyt Huffman, MS

Ariel K. Smits, MD, MPH

July 2005

This report may not be used, in whole or in part, as the basis of the development of clinical practice guidelines and other quality enhancement tools, or 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.

AHRQ is the lead Federal agency charged with supporting research designed to improve the quality of health care, reduce its cost, address patient safety and medical errors, and broaden access to essential services. AHRQ sponsors and conducts research that provides evidence-based information on health care outcomes; quality; and cost, use, and access. The information helps health care decisionmakerpatients and clinicians, health system leaders, and policymakersmake more informed decisions and improve the quality of health care services.