Robinson KA, Chou R, Berkman ND, Newberry SJ, Fu R, Hartling L, Dryden D, Butler M, Foisy M, Anderson J, Motu’apuaka ML, Relevo R, Guise JM, Chang S. Integrating Bodies of Evidence: Existing Systematic Reviews and Primary Studies. Methods Guide for Comparative Effectiveness Reviews (Prepared by the Scientific Resource Center under Contract No. 290-2012-00004-C). AHRQ Publication No. 15-EHC007-EF. Rockville, MD: Agency for Healthcare Research and Quality. February 2015.
http://www.effectivehealthcare.ahrq.gov/ehc/products/597/2049/integrating-evidence-report-150226.pdf
The increasing number of systematic reviews, along with the time and money required to undertake a review, has motivated a desire to incorporate existing systematic reviews in a new review. In considering the integration of existing systematic reviews into new reviews, there is a tradeoff between accepting the results of the prior review and needing to either complete again the selected elements of the review or the review in its entirety. The key is to find the right balance in terms of an efficient and unbiased approach to conducting and reporting the integration of existing systematic reviews into the new review. In this working document, we have provided preliminary guidance to help find that balance.
