This report may be used, in whole or in part, as the basis for 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 decisionmakers— patients and clinicians, health system leaders, and policymakers—make more informed decisions and improve the quality of health care services. Systematic Evidence Review Number 11 Hormone Replacement Therapy and Risk of Venous Thromboembolism 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. 290-97-0018 Task Order No. 2 Technical Support of the U.S. Preventive Services Task Force Prepared by: Oregon Health Sciences University Evidence-based Practice Center, Portland, Oregon Jill Miller, MD Benjamin K.S. Chan, MS Heidi Nelson, MD, MPH August 2002 Preface The Agency for Healthcare Research and Quality (AHRQ) sponsors the development of Systematic Evidence Reviews (SERs) through its Evidence-based Practice Program. With ∗ guidance from the third U.S. Preventive Services Task Force (USPSTF) and input from Federal partners and primary care specialty societies, two Evidence-based Practice Centers—one at the Oregon Health Sciences University and the other at Research Triangle Institute-University of North Carolina—systematically review the evidence of the effectiveness of a wide range of clinical preventive services, including screening, counseling, immunizations, and chemoprevention, in the primary care setting. The SERs—comprehensive reviews of the scientific evidence on the effectiveness of particular clinical preventive services—serve as the foundation for the recommendations of the third USPSTF, which provide age- and risk-factor- specific recommendations for the delivery of these services in the primary care setting. Details of the process of identifying and evaluating relevant scientific evidence are described in the “Methods” section of each SER. The SERs document the evidence regarding the benefits, limitations, and cost-effectiveness of a broad range of clinical preventive services and will help to further awareness, delivery, and coverage of preventive care as an integral part of quality primary health care. AHRQ also disseminates the SERs on the AHRQ Web site (http://www.ahrq.gov/uspstfix.htm) and disseminates summaries of the evidence (summaries of the SERs) and recommendations of the third USPSTF in print and on the Web. These are available through the AHRQ Web site (http://www.ahrgq.gov/uspstfix.htm), through the National Guideline Clearinghouse (http://www.ncg.gov), and in print through the AHRQ Publications Clearinghouse (1-800-358-9295). We welcome written comments on this SER. Comments may be sent to: Director, Center for Practice and Technology Assessment, Agency for Healthcare Research and Quality, 6010 Executive Blvd., Suite 300, Rockville, MD 20852. Carolyn M. Clancy, M.D. Robert Graham, M.D. Acting Director Director, Center for Practice and Agency for Healthcare Research and Quality Technology Assessment Agency for Healthcare Research and Quality ∗ The USPSTF is an independent panel of experts in primary care and prevention first convened by the U.S. Public Health Service in 1984. The USPSTF systematically reviews the evidence on the effectiveness of providing clinical preventive services--including screening, counseling, immunization, and chemoprevention--in the primary care setting. AHRQ convened the third USPSTF in November 1998 to update existing Task Force recommendations and to address new topics. iii The authors of this report are responsible for its content. Statements in the report should not be construed as endorsement by the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services of a particular drug, device, test, treatment, or other clinical service. iv Contents Structured Abstract ..............................................................................................................1 Systematic Evidence Review Chapter 1. Introduction .......................................................................................................3 Burden of Suffering ...................................................................................................3 Prior Recommendations.............................................................................................3 Analytic Frameworks and Key Questions .................................................................4 Chapter 2. Methods.............................................................................................................5 Literature Search Strategy..........................................................................................5 Inclusion/Exclusion Criteria ......................................................................................5 Size of Literature Reviewed.......................................................................................6 Data Extraction and Synthesis ...................................................................................6 Chapter 3. Results ...............................................................................................................9 Hormone Replacement Therapy Studies ...................................................................9 Randomized Controlled Trials.........................................................................9 Case-Control Studies .....................................................................................11 Cohort Study ..................................................................................................16 Meta-Analysis of HRT Studies................................................................................17 Studies of Selective Estrogen Receptor Modulators (SERMs)................................18 Chapter 4. Discussion ........................................................................................................21 Conclusions..............................................................................................................21 Limitations of the Literature ....................................................................................22 Future Research .......................................................................................................23 Acknowledgements............................................................................................................25 References..........................................................................................................................26 Appendix 1a. Search Strategy for Effects of Hormone Replacement Therapy on Coagulation...........................................................................................39 Appendix 1b. Search Strategy for Hormone Replacement Therapy Randomized Controlled Trials.................................................................................41 Appendix 1c. Search Strategy for Selective Estrogen Receptor Modulators (SERMs)...............................................................................................42 Appendix 2. Hormone Replacement Therapy and Venous Thromboembolism Search Results..........................................................................................................43 v Appendix 3. Criteria for Grading the Internal Validity of Individual Studies..................44 Appendix 4. Evidence Tables (1-4) ..................................................................................46 Figures Figure 1. Benefits of Hormone Replacement Therapy: Analytic Framework 1...............32 Figure 2. Adverse Effects of Hormone Replacement Therapy: Analytic Framework 2 ............................................................................................................33 Figure 3. Risk for Venous Thromboembolism by Year of HRT Use...............................34 Figure 4. Meta-analysis of Estrogen Studies ....................................................................35 Tables Table 1. Studies of Hormone Replacement Therapy Included in Meta-analysis .............36 Table 2. Trials of Selective Estrogen Receptor Modulaters Reporting Thrombotic Events...................................................................................................37 Table 3. Summary of Evidence.........................................................................................38 vi Contents Structured Abstract ..............................................................................................................1 Systematic Evidence Review Chapter 1. Introduction .......................................................................................................3 Burden of Suffering ...................................................................................................3 Prior Recommendations.............................................................................................3 Analytic Frameworks and Key Questions