Lifecycles of Cochrane Systematic Reviews (2003–2024): A Bibliographic Study

Abstract

Background and Objectives

The relevance of Cochrane systematic reviews depends on timely completion and updates. This study aimed to empirically assess the lifecycles of Cochrane reviews published from 2003 to 2024, including transitions from protocol to review, update patterns, and withdrawals.

Methods

We extracted data from Cochrane Library publications between 2003 and 2024. Each review topic was identified using a unique six-digit DOI-based ID. We recorded protocol publication, review publication, updates, and withdrawals (i.e., removed from the Cochrane Library for editorial or procedural reasons), calculating time intervals between stages and conducting subgroup analyses by review type.

Results

Of 8137 protocols, 71.9% progressed to reviews (median 25.7 months), 2.4% were updated during the protocol stage, and 10.0% were withdrawn. Among 8477 reviews, 64.3% were never updated by the time of our analysis; for those updated at least once, the median interval between updates was 57.2 months. Withdrawal occurred in 2.5% of reviews (median 67.6 months post-publication). Subgroup analyses showed variation across review types; diagnostic and qualitative reviews tended to have longer protocol-to-review times than other types of reviews.

Conclusions

Cochrane reviews show long development and update intervals, with variation by review type. Greater use of automation and targeted support may improve review efficiency and timeliness.