How to decide whether a systematic review is stable and not in need of updating: Analysis of Cochrane reviews.

Background: It is challenging to keep systematic reviews (SR) current and updated. Cochrane designated some of its SRs as "stable," that is, not in need of updating. The issue of stabilizing an SR is an important in research synthesis, because it could help reduce research waste. The aim of this study was to analyze publicly available justifications for stabilizing a Cochrane review, with the ultimate goal of helping to make decisions about whether the update of any SR is warranted.
Methods: We analyzed Cochrane reviews labeled as stable in Archie, Cochrane's system for managing the editorial/publishing process. From the "What's new" section of the reviews in the Cochrane Library, we extracted justification for stabilization.
Results: We included 545 Cochrane reviews labeled in Archie as stable on October 28, 2019. The most common of the five reasons for stabilization was that "last search did not identify any potentially relevant studies likely to change conclusions" (N = 99; 18%), followed by "research area no longer active" (N = 86; 16%), "review is or will be superseded" (N = 41; 7.5%), "evidence is conclusive" (N=35; 6.4%), and "intervention no longer in general use" (N = 34; 6.2%). For the 269 (49%) Cochrane reviews, we considered that the justification for stabilization was not clearly described, that is, sufficiently informative.
Conclusions: Cochrane reviews would benefit from more transparency and consistency in publicly available justifications for stabilizing reviews. Further work in this field will help make decisions about the futility of further research and deciding on enough evidence in the field of research synthesis.
(© 2020 John Wiley & Sons Ltd.)