Factors predicting completion and time to publication of Cochrane reviews

BACKGROUND: Cochrane reviews are regarded as scientifically rigorous, yet a review’s time to publication can be affected by factors such as the statistical significance of the findings. When this happens, misrepresentation of the literature and subsequent inappropriate decisions may result. We aimed to examine the factors associated with the time to publication of Cochrane reviews. METHODS: Review protocols published in issue 2, 2000, of the Cochrane Database of Systematic Reviews were included in this analysis if the corresponding review was published by issue 1, 2008. We used univariable and multivariate analyses to examine the time from publication of the protocol to publication of the first review and review-related factors predicting the time to publication. RESULTS: Of 118 eligible protocols published in issue 2, 2000, we identified 93 Cochrane reviews that had been published by January 2008. Of these, 36 (39%) were updates. The median time to publication was 1.63 years (range 0.15–7.31 years). A change in authors between publication of the protocol and publication of the final review was associated with longer time to publication (p = 0.002), whereas updated reviews were associated with shorter time to publication (p = 0.030). INTERPRETATION: In our study, 79% of the Cochrane protocols were published as a final review, and some Cochrane reviews took over 7 years from publication of the protocol to publication of the final review. Strategies to increase the number of published Cochrane reviews and decrease the time to publication should be considered, such as providing support to reviewers when a change in authorship occurs.