In 1993 the Cochrane Collaboration, an international non-profit organization aiming at producing, updating and disseminating systematic reviews, was founded. Several years later, in 1999, the Chinese Cochrane centre opened in Chengdu, to provide support to (1) Chinese researchers willing to produce reviews and (2) politicians and practitioners willing to start using the results in daily practice. We searched PubMed and the database of the Chinese Cochrane Centre to retrieve data on the overall number of articles and reviews produced in the Chinese language for the period 1990 to 2006. Although the number of reviews increased substantially since the year 2000, the percentage of reviews in the overall number of articles indexed in PubMed remains modest.
Objective To assess the effects on labour, maternal, and neonatal outcomes of different techniques and drugs for analgesia during labour. Methods We searched The Cochrane Library (Issue 4, 2006) , MEDLINE (Jan. 1978 to Oct. 2006) and CBMdisc (Jan. 1980 to Oct. 2006) to collect the current best evidence of labor analgesia. Results We included eight Cochrane systematic reviews and six other meta-analyses. The evidence showed that epidural analgesia was associated with a longer second stage of labour, more frequent oxytocin augmentation, higher incidence of instrumental vaginal delivery and maternal fever. But it was unlikely to increase the risk of caesarean section. Conclusion Epidural analgesia is superior to other approaches.
Objective ① To document the way in which allocation concealment is described and coded for studies included in Cochrane Reviews.②To feed back any gaps or miscodings to individual review groups.③ To suggest changes and expansions to advice on how to code and describe allocation concealment methods.Methods The coding and description of methods of allocation concealment for studies included in all 1 596 reviews on issue 1, 2003 of The Cochrane Library are being extracted.So far results are available for 10.8% (173/1 596) of reviews containing 1 844 studies, from 10 Collaborative Review Groups (CRGs).Discrepancies, and inconsistencies with the Cochrane Reviewers’ Handbook, are being documented and analysed.Results The current coding of the adequacy of allocation concealment in studies included in Cochrane reviews is not likely to be very accurate.This is due to failure to describe methods of allocation concealment (38.6% of the sample of 1 844 studies) as well as miscoding (at least an additional 9.2%).The most common method for studies coded A was some variation of envelope use (133/675-19.7% of all A codes). The most common "method" for studies coded B was method unclear or not described in the report of the study (426/665, 64% of all B codes).Conclusions Since adequate allocation concealment is so important in protecting against bias in randomised controlled trials, it needs to be accurately coded and described.We need to improve how this is done for studies included in Cochrane Reviews.Since over half the studies coded as D were likely to have been where reviewers omitted to enter a code, the default should be changed from D to "code not supplied".Structural changes to RevMan are suggested-ideally the addition of a separate new study quality assessment table with fixed headings as well as the facility to enter free text.Suggestions for improving coding in particular reviews will be fed back to CRGs in the next stages of this project.Suggestions for additions to the Cochrane Reviewers’ Handbook are also made.
Objective To detect the false-negative results of cumulative meta-analyses of Cochrane Urology Group with the trial sequential analysis (TSA). Methods The Urology Group of The Cochrane Library (Issue 6, 2016) was searched to collect meta-analyses with negative results. Two researchers independently screened literature and extracted data of included meta-analyses. Then, TSA was performed using TSA software version 0.9 beta. Results A total of 11 papers involving 12 meta-analyses were included. The results of TSA showed that, four (33%) out of 12 meta-analyses were potentially false-negative results for failing to surpass the trial sequential monitoring boundary and to reach the required information size. Conclusion Some of the negative results of systematic reviews from Cochrane Urology Group was false-negative. TSA can help researchers to identify the false-negative results of meta-analyses.
ObjectiveTo investigate the extent of overlap between Chinese systematic reviews (SRs) and Cochrane SRs in the field of stroke. MethodsThe CNKI, WanFang Data, CBM and Cochrane Library databases were searched to collect Chinese SRs and Cochrane SRs in the field of stroke published from 2012 to 2022. By extracting population (P), intervention (I), comparison (C), and outcome (O) of all interventional SRs in the stroke field to analyse the extent of overlap of SRs. The basic information and research information of SRs with overlapping PICOs were further extracted to conduct descriptive analysis. ResultsA total of 1 303 SRs were included, involving 1 192 Chinese SRs and 111 Cochrane SRs in the field of stroke. The overlapping analysis found that 128 Chinese SRs overlapped with 29 (26.1%) of the 111 Cochrane SRs. Most (127/128, 99.2%) Chinese SRs were published later than Cochrane SRs. The year of publication of overlapping SRs showed a trend of increasing year by year. ConclusionThe SR work carried out by scholars in China has the problem of overlapping studies that cannot be ignored, and the lack of strict regulation and guidance in methods such as registration, protocol writing, and literature search has resulted in a great waste of resources. It is necessary to further strengthen regulatory constraints and guidance, adhere to problem orientation and quality awareness, strengthen SR training, and reduce overlapping research.