Background The association between osteoarthritis (OA) and mortality has been a subject of interest, as this may lead us to a better understanding of the pathogenesis of OA. Unfortunately, study results have been controversial.
Objectives To conduct a systematic review to determine the true association between OA and mortality.
Methods A systematic search was performed in the databases MEDLINE, EMBASE, COCHRANE, Web of Science, ScienceDirect, CINAHL and Academic Search Premier up to October 2011. Two independent reviewers identified studies that reported mortality for OA patients, compared with a non-OA population. Study quality was also assessed Information on study design, patient characteristics, OA status, duration of follow-up, mortality assessment and outcomes were extracted for each study.
Results The electronic databases yielded 1598 individual articles of which 1387 articles were excluded on the basis of title and 116 articles on the basis of abstracts. Ninety-five articles were screened full-text and only 27 articles met the inclusion criteria. Five articles were additionally excluded due to multiple publications for the same population, the lack of OA specific information or short follow-up time. Finally, 22 studies, investigating 23 patient populations, were included in the present review. Most studies involved knee or hip OA (n=17). Comparisons were mostly made with the general population using information from the country’s bureau of statistics. The quality of these studies varied widely. Thirteen studies reported mortality in 14 study populations, receiving either total knee or hip arthroplasty; the majority of these studies found lower mortality rates for OA patients. Four studies, generally of low quality, of which three hospital based found increased mortality rates, whereas one study, in OA patients consulting their general practitioners, did not. Five studies were based in the general population; two high quality studies reported higher mortality rates, while the other studies (of a varying quality) reported lower and equal mortality rates for OA cases.
Conclusions The heterogeneous quality of the studies has unfortunately resulted in important limitations to our interpretation of the evidence. The association between OA and mortality appears to be complex, depending on the phenotype. Factors, such as selection bias, care seeking behavior, OA subtype, etc could account for the observed differences. Further studies are warranted.
Disclosure of Interest None Declared