The methodological quality was low and conclusions discordant for meta-analyses comparing proximal humerus fracture treatments: a meta-epidemiological study

Objective To investigate the association between methodological quality and reported conclusions of meta-analyses comparing operative with non-operative treatments for proximal humerus fractures. Study design and setting Cross-sectional meta-epidemiological study. We searched EMBASE, PubMed, The Cochrane Library, and Web of Science for systematic reviews with meta-analyses comparing non-operative with operative treatments for proximal humerus fractures. Methodological quality was assessed using AMSTAR2 and the reported conclusions were scored for three outcome domains (functional outcome, quality of life, and harm) on a scale from 1 to 6. The Mann-Whitney and Kruskal-Wallis tests were used to investigate the association between methodological quality and reported conclusions. Results We included 21 systematic reviews: 19 pairwise meta-analyses and 2 network meta-analyses, although there are only 8 published randomized controlled trials. Most (n = 18) of the meta-analyses were rated as critically low quality, while the remaining 1 was rated as high quality. The conclusions were discordant for all three outcome domains, even for meta-analyses reporting similar inclusion criteria. We could not perform most of the statistical tests due to the predominantly critically low quality. Conclusion The methodological quality was so predominantly critically low that it was not possible to evaluate the association between methodological quality and reported conclusions.