Assessing the methodological and reporting quality of network meta-analyses in Chinese medicine

Background: An increasing number of network meta-analyses (NMAs) in traditional Chinese medicine (TCM) have been published recently, but the quality of them was lack of assessment. This study aims to evaluate the methodological and reporting quality of NMAs in TCM. Methods: Six electronic databases, including PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), Embase, China National Knowledge Infrastructure (CNKI), Wanfang and Chinese Biomedical Literature Database (CBM) from inception to January 2018, were searched. NMAs of TCM were included. A measurement tool to assess the methodological quality of systematic reviews (AMSTAR) and the PRISMA Extension Statement for Reporting of Systematic Reviews Incorporating Network Meta-analyses of Health Care Interventions (PRISMA-NMA) were used to assess the methodological and reporting quality of the included NMAs. Results: A total of 40 NMAs, including 2535 randomized controlled trials (RCTs), were included. They were published between December 2012 and November 2017. The median score and interquartile range of methodological and reporting quality was 7 (6-8) and 22 (19.1-27.1). Serious methodological flaws existed in the following aspects: the status of publication (22.5%), a list of studies provided (0%), assessment of publication bias (37.5%), and conflicts of interest (12.5%). Several items need to be improved in reporting, especially for Protocol and registration (2.5%), Data items (22.5%), Risk of bias across studies (Methods section) (37.5%), Results of individual studies (27.5%), Risk of bias across studies (Results section) (40%), Results of additional analyses (35%), and Funding (15%). Conclusions: The methodological and reporting quality of NMAs in TCM is moderate. Identified shortcomings of published NMAs should be taken into consideration in further trainings of authors and editors of NMAs in TCM. Future researchers should be encouraged to apply PRISMA-NMA, and a recognized tool for the assessment of NMA methodology was wanted.