Assessing the validity of a rapid review against a systematic literature review. A comparison of systematic literature reviews done by Cochrane with rapid reviews and the impact on meta-analyses results.

Introduction: Rapid reviews (RRs) offer a less rigorous and methodical approach to the process of reviewing literature in comparison to systematic reviews (SRs), which are currently a gold standard.

Materials And Methods: Three different, expedited strategies of the review process were designed in the different scopes, already reviewed in Cochrane's SRs. Then, the results of our literature searches and the study selection process were compared to the ones from SRs. The final step was assessing the impact of losing some studies on the final results of meta-analyses.

Results: In RR, the initial number of references to be reviewed was reduced by half, and the inclusion list was recreated with 84% efficiency. Three out of 19 studies were missed, all having high risk of bias. Studies missed in RR were included in Cochrane's meta-analyses for 23 separate outcomes, and their lack impacted significantly the final results, or the possibility to run meta-analyses, in four cases. In RR, 89% of trials included in the SR were captured (24/27); missing the three studies did not impact the final results of the meta-analyses. In RR, the list of included studies overlapped completely with Cochrane's, despite a significantly lower workload.

Conclusions: A prompt and cost-effective methodology may lead to the identification of pertinent evidence in support of healthcare policy; however, it is essential to conscientiously account for potential biases in the analysis.