Methodological Quality and Risk of Bias of Systematic Reviews and Meta-Analyses on Stem Cells for Knee Osteoarthritis: A Cross-Sectional Survey

Abstract Background: Clinical guidelines need high-quality studies to support clinical decision-making, in which the evidence often was collected from systematic reviews (SRs) and/or meta-analyses (MAs). At present, the methodological quality and risk of bias (RoB) of SRs/MAs on stem cell therapy for the treatment of knee osteoarthritis (KOA) has been poorly investigated. This study aims to strictly evaluate the methodological quality and RoB in SRs/MAs of stem cell therapy for KOA.Methods: Four electronic databases (PubMed, Embase, Cochrane Library, and Web of Science databases) were searched, from inception to October 5th, 2021. SRs/MAs involving RCTs or cohort studies on stem cell therapy for the treatment of KOA were included. The methodological quality and RoB were assessed using AMSTAR 2 and ROBIS tool respectively. Results: In total, 22 SRs/MAs were included. According to the results obtained by AMSTAR 2 tool, all SRs/MAs were rated as “Critically low”. Main methodological weaknesses were as follows: eight items accounted for more than 50% of “No”, including Items 2 Protocol registration (81.82%), Item 7 Study exclusion and justification (86.36%) and Item 15 Investigation and discussion of publication bias (63.64%) were critical items. ROBIS-based RoB assessment showed that all the SRs/MAs were rated as “High”.Conclusions: The overall methodological quality of the SRs/MAs concerning the application of stem cell therapy in treating KOA is “Critically low”, while the RoB is high. It is difficult to provide effective evidence for the formulation of guidelines for KOA treatment. We suggest that the relevant methodological quality assessment should be carried out in the future before the SRs/MAs are used as clinical evidence.PROSPERO registration number: CRD42021246924