title: The evolution of a new publication type: Steps and challenges of producing overviews of reviews.
abstract: BACKGROUND
  To date, the Cochrane Child Health Field has published 18 overviews of reviews in our journal, Evidence-based Child Health: A Cochrane Review Journal. In this article, we highlight some of the logistical and methodological challenges of producing such syntheses. As this is a new and evolving publication type, we hope that our experience will benefit others who engage in this process. Current Methods: We discuss the process we have developed to produce overviews of reviews relevant to our mandate, including identification of the research question, establishment of the author team, selection of outcomes and included SRs, and presentation of findings. Ongoing Development: We discuss the lessons we have learned, outstanding challenges for overview authors, and the limitations of overviews.
  
  
  CONCLUSIONS
  Overviews of reviews are only as good as the SRs and primary studies on which they are based; gaps or lack of currency in this evidence will weaken the overview of reviews. Future directions in this work must address questions of bias and loss of information. Methods for overviews of reviews targeted for specific groups, such as children, need more elaboration. Copyright © 2011 John Wiley & Sons, Ltd.
authors.affiliation: Cochrane Child Health Field, Department of Pediatrics, University of Alberta, Edmonton, AB, Canada. dthomson@ualberta.ca.
authors.forename: Denise
authors.initials: D
authors.lastname: Thomson
authors.affiliation: Alberta Research Centre for Health Evidence, Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.
authors.forename: Kelly
authors.initials: K
authors.lastname: Russell
authors.affiliation: Cochrane Comparing Multiple Interventions Methods Group and Department of Family Medicine, SUNY Upstate Medical University, Syracuse, New York, U.S.A.
authors.forename: Lorne
authors.initials: L
authors.lastname: Becker
authors.affiliation: Manitoba Institute of Child Health and Department of Pediatrics, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Terry
authors.initials: T
authors.lastname: Klassen
authors.affiliation: Alberta Research Centre for Health Evidence, Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.
authors.forename: Lisa
authors.initials: L
authors.lastname: Hartling
keywords: evidence synthesis; evidence‐based pediatrics; overviews of reviews; umbrella reviews