Half of Cochrane reviews were published more than two years after the protocol

Article type
Authors
Andersen MZ1, Gülen S1, Fonnes S1, Andresen K1, Rosenberg J1
1Cochrane Colorectal Group
Abstract
Background:
Cochrane reviews are known for their rigorous methodology and high quality, and authors must follow specific guidelines to ensure this. Cochrane reviews can also require longer time to complete than other systematic reviews. It is important that Cochrane reviews are up to date as they have a significant influence on clinical guidelines.

Objectives:
This study aimed to examine the time from publication of a protocol for a Cochrane review to publication of the actual Cochrane review for the entire Cochrane Database of Systematic Reviews.

Methods:
This study was reported in line with the STROBE guideline. Cochrane reviews from the Cochrane Database of Systematic Reviews published between 1995-2019 were assessed. Characteristics of the reviews were extracted and time from publication of protocol to publication of review was calculated. These times were grouped for relevant characteristics and visualized through charts and tables to illustrate trends.

Results:
Of the total 8,201 reviews in the database, 6,764 were included. The median publication time was two years (range 0 days to 21.7 years). Reviews that were published more than five years after the protocol made up 11% of all included reviews, while 19% of reviews were published within a year. The median publication time for the individual Cochrane Review Groups ranged from 15-39 months.

Conclusion:
Half of Cochrane reviews were published later than Cochrane’s aim of 2 years. Furthermore, the Cochrane Review Groups’ times from publication of protocol to publication of review varied widely.

Patient or healthcare consumer involvement:
This study is important as it highlights an issue with long time from consumers' need for answer of a review question until the results are available.