When and how to update systematic reviews

Abstract

Governments, funding agencies, academic institutions, and health care policy makers are increasingly investing in the design, development, and dissemination of systematic reviews (SRs) to inform clinical practice guidelines, ethical guidance of clinical research, and health care practice and policy. SRs need to be sensitive to the dynamic nature of new evidence, such as published papers. The emergence of new evidence over time may undermine the validity of conclusions and recommendations in any given SR and subsequent practice guideline. This issue has only started to be more seriously considered during the last decade or so. Now it is clear that the use of out-dated evidence can lead to a waste of resources, provision of redundant, ineffective or even harmful health care. The author of this dissertation and his colleagues conducted and published three empirical studies and two conceptual articles (in six peer-reviewed journal publications), which addressed the methodologic aspects of when and how to update SRs. This PhD project provides a summary of these publications. The work described herein has had a significant impact on raising awareness and initiating new research efforts for keeping SRs up-to-date. Publication 1 proposed the first formal definition of what constitutes an update of a SR. The article presented distinguishing features of an updated vs. not updated or a new review. Publication 2 (or Publication 3) systematically reviewed methods, techniques, and strategies describing when and how to update SRs (Study #1). Publication 4, an international survey (Study #2), identified and described updating practices and policies of organisations involved in the production and commission of SRs. Publication 5 reviewed the knowledge and efforts in updating SRs and provided guidance for authors and SR groups as to when and how to update comparative effectiveness reviews produced by the Agency for Healthcare Research and Quality’s (AHRQ) Evidence-based Practice Centres (EPCs) throughout North America. Publication 6 (Study #3) described the development, piloting, and feasibility of a surveillance system to assess the need for updating comparative effectiveness reviews produced by the AHRQ’s EPC Program. This surveillance method has proved to be an efficient approach for prioritising SRs with respect to updating need