Prepared for:

Agency for Healthcare Research and Quality

U.S. Department of Health and Human Services

2101 East Jefferson Street

Rockville, MD 20852

http://www.ahrq.gov

Contract No. 290-97-0014

Prepared by:

Duke University Evidence-based Practice Center

Center for Clinical Health Policy Research

Douglas C. McCrory, M.D., M.H.Sc.

Principal Investigator

Cynthia Brown, M.D.

Rebecca N. Gray, D.Phil.

Ruth E. Goslin, M.A.T.

Jane T. Kolimaga, M.A.

Neil R. MacIntyre, M.D.

Eugene Z. Oddone, M.D., M.H.Sc.

David B. Matchar, M.D.

Investigators

AHRQ Publication No. 01-E003

March 2001

ISBN: 1-58763-050-8

ISSN: 1530-4396

On December 6, 1999, under Public Law 106-129, the Agency for Health Care Policy and Research (AHCPR) was reauthorized and renamed the Agency for Healthcare Research and Quality (AHRQ). The law authorizes AHRQ to continue its research on the cost, quality, and outcomes of health care and expands its role to improve patient safety and address medical errors.

This report may be used, in whole or in part, as the basis for development of clinical practice guidelines and other quality enhancements 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.