Osteoarthritis and all-cause mortality in worldwide populations: grading the evidence from a meta-analysis

The objective of this study is to investigate the association between osteoarthritis (OA) and all-cause mortality in worldwide populations and to develop recommendations according to GRADE evidence levels. Literature search through Nov 2015 was performed using the electronic databases (including MEDLINE, EMBASE, EBSCO and Cochrane library). The prospective cohort trials that investigated the association between the symptomatic OA (SxOA) or radiological OA (ROA) and all-cause mortality were identified. Hazard ratios (HR) of all-cause mortality in patients with RxOA or ROA were pooled respectively. The evidence quality was evaluated using the GRADE system, while the recommendations were taken according to the quality. Nine of the published literature met the eligible criteria. Meta-analysis revealed that there was no significant difference in the association between SxOA and all-cause mortality (HR = 0.91, 95% CI: 0.68-1.23) and between ROA and all-cause mortality (HR = 1.13, 95% CI: 0.95-1.35). The overall GARDE evidence quality was very low, which will lower our confidence in taking recommendations. To summarize, there was no reliable and confident evidence existed currently in respect of the association between OA and all-cause mortality. Due to the very low level of evidence quality currently, high-quality studies are still required.