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.

Background In view of the inadequacy and incompleteness of currently-reported animal experiments and their overall poor quality, we retrospectively evaluated the reporting quality of animal experiments published in Chinese journals adhering to the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines. Results The databases CNKI, WanFang, VIP, and CBM were searched from inception until July 2018. Two appropriately-trained reviewers screened and extracted articles independently. The ARRIVE guidelines were used to assess the quality of the published reports of animal experiments. The compliance rate of every item was analyzed relative to their date of publication. A total of 4342 studies were included, of which 73.0% had been cited <= 5 times. Only 29.0% (1261/4342) were published in journals listed in the Chinese Science Citation Database. The results indicate that the compliance rate of approximately half of the sub-items (51.3%, 20/39) was less than 50%, of which 65.0% (13/20) was even less than 10%. Conclusions The reporting quality of animal experiments in Chinese journals is not at a high level. Following publication of the ARRIVE guidelines in 2010, the compliance rate of the majority of its requirements has improved to some extent. However, less attention has been paid to the ethics and welfare of experimental animals, and a number of specific items in the Methods, Results, and Discussion sections continue to not be reported in sufficient detail. Therefore, it is necessary to popularize the ARRIVE guidelines, advocate researchers to adhere to them in the future, and in particular promote the use of the guidelines in specialized journals in order that the design, implementation, and reporting of animal experiments is promoted, to ultimately improve their quality.