Using Existing Systematic Reviews in Complex Systematic Reviews

20 May 2008 | Volume 148 Issue 10 | Pages 776-782

Systematic reviewers increasingly must decide whether and how to incorporate existing systematic reviews into complex systematic reviews that are commissioned to support clinical guideline development or for other health policy uses. To date, however, this issue has been largely unexamined. Reviewers seeking to incorporate existing reviews into new reviews face a set of important questions:

Can this practice adhere to systematic review principles? Will it save time? When should it be avoided? Will it produce valid results and be acceptable to users? Drawing from their collective experience, the authors outline a series of steps that can help reviewers reach reasoned decisions about the incorporation of existing systematic reviews and enumerate potential hazards to consider in doing so. They highlight issues surrounding the main steps reviewers must undertake, including locating existing reviews; assessing their relevance to the new review; assessing the quality of relevant reviews; determining how to incorporate high-quality, relevant existing systematic reviews; and clearly reporting the methods used and the results from this process. Further specification of methods, including the development of reporting standards for this approach, is needed.

Author and Article Information

From Oregon Evidence-based Practice Center, Kaiser Permanente Center for Health Research, and Oregon Health & Science University, Portland, Oregon; Southern California Evidence-Based Practice Center and RAND Corporation, Santa Monica, California; and Johns Hopkins Evidence-based Practice Center and Johns Hopkins University, Baltimore, Maryland.

Acknowledgment: The authors thank David Hopkins and Randy Elder, Centers for Disease Control and Prevention Community Task Force, for their initial contribution to the concepts underlying this paper. They also thank Carolyn Summerbell, University of Teesside and Cochrane Collaboration, United Kingdom; Lesley Gillespie, Cochrane Collaboration, New Zealand; Robert Weir and Susan Bidwell, New Zealand Health Technology Assessment; and Paul Wilson and Alison Eastwood, UK Center for Reviews and Dissemination, University of York, United Kingdom, for sharing their experiences and perspectives and providing confirmation or additional insights. The contents of this article are not meant to represent the perspectives of these individuals nor the organizations for which they conduct reviews. Finally, the authors thank Ed Reid for his invaluable editorial assistance.

Potential Financial Conflicts of Interest: None disclosed.

Requests for Single Reprints: Evelyn P. Whitlock, MD, MPH, Center for Health Research, Kaiser Permanente Northwest, 3800 North Interstate Avenue, Portland, OR 97227; e-mail, evelyn.whitlock{at}kpchr.org.

Current Author Addresses: Drs. Whitlock and Lin: Center for Health Research, Kaiser Permanente Northwest, 3800 North Interstate Avenue, Portland, OR 97227.

Dr. Chou: Oregon Evidence-based Practice Center, Oregon Health Science University, 3181 Southwest Sam Jackson Park Road, Mail Code BICC, Portland, OR 97239.

Dr. Shekelle: Southern California Evidence-based Practice Center, West Los Angeles Veterans Affairs Medical Center, 10833 Wilshire Boulevard, Los Angeles, CA 90067.

Ms. Robinson: Evidence-based Practice Center, Johns Hopkins University, 1830 East Monument Street, Room 8069, Baltimore, MD 21205.