Search

Rapid reviews have been widely employed to support timely decision-making, and limiting the search date is the most popular approach in published rapid reviews. We assessed the accuracy and workload of search date limits on the meta-analytical results to determine the best rapid strategy. The meta-analyses data were collected from the Cochrane Database of Systematic Reviews (CDSR). We emulated the rapid reviews by limiting the search date of the original CDSR to the recent 40, 35, 30, 25, 20, 15, 10, 7, 5, and 3 years, and their results were compared to the full meta-analyses. A random sample of 10% was drawn to repeat the literature search by the same timeframe limits to measure the relative workload reduction (RWR). The relationship between accuracy and RWR was established. We identified 21,363 meta-analyses of binary outcomes and 7683 meta-analyses of continuous outcomes from 2693 CDSRs. Our results suggested that under a maximum tolerance of 5% and 10% on the bias of magnitude, a limit on the recent 20 years can achieve good accuracy and at the same time save the most workload. Under the tolerance of 15% and 20% on the bias, a limit on the recent 10 years and 15 years could be considered. Limiting the search date is a valid rapid method to produce credible evidence for timely decisions. When conducting rapid reviews, researchers should consider both the accuracy and workload to make an appropriate decision.

The author should give careful consideration to the study eligibility criteria of systematic reviews (SRs) and follow it after review protocol development to reduce the possibility of manipulation of inclusion. Our aim was to investigate the prevalence of differences in study eligibility criteria between non-Cochrane SRs and their pre-registered protocols on PROSPERO, and determined what changes were involved as well as whether those changes were explained. We searched the protocols registered on PROSPERO platform in the year of 2018 and then selected these protocols which full-text have been published up to June 9, 2020. A random sample (n = 100) was included. Published full-texts were identified through the protocol's final publication citation. The following five key components of study eligibility criteria were compared: participants, intervention(s)/exposure(s), comparator(s), types of study design, and outcome(s). A total of 90% of included SRs exhibited differences in study eligibility criteria, and 59/90 altered in no less than two key components. Only one SR reported and explained the rationale for changes to the individual key component (the definition of exposure). The "Outcome(s)" exhibited the greatest variation, with changes in 61% of the SRs. The "Comparator(s)/control" exhibited the smallest variation, with changes in 20% of the SRs. Differences in study eligibility criteria between the non-Cochrane SRs and their protocols registered on PROSPERO were widespread but were seldom explained. Authors themselves, PROSPERO platform, as well as peer-review journals and their peer-reviewers should play a role in further improving transparency.