Does symptomatic knee osteoarthritis increase the risk of all-cause mortality? Data from four international population-based longitudinal surveys of aging.

OBJECTIVE

This study aimed at examining the association between symptomatic knee osteoarthritis and all-cause mortality based on four population-based longitudinal surveys.

METHOD

Data were retrieved from the English Longitudinal Study of Aging (ELSA), the Survey of Health, Aging and Retirement in Europe (SHARE), the Korean Longitudinal Study of Aging (KLoSA), and the Indonesian Family Life Survey (IFLS). The association between symptomatic knee osteoarthritis and all-cause mortality over the 8- to 12-year follow-up period was assessed using Cox-proportional hazard models.

RESULTS

In the entire sample of 59,522 participants (4823 with symptomatic knee osteoarthritis; 54,699 without symptomatic knee osteoarthritis [control group]; mean age: 61.8 years; female percentage: 55.3%), 8375 died (937 in the symptomatic knee osteoarthritis group, 7438 in the control group) during the follow-up period. Patients with symptomatic knee osteoarthritis had a higher risk of all-cause mortality than control group without adjusting for potential confounders in each survey, and the unadjusted hazard ratios (HRs) of all-cause mortality were 1.32 (95% confidence interval [CI] 1.18 to 1.47) in ELSA, 1.40 (95%CI 1.24 to 1.56) in SHARE, 1.25 (95%CI 1.06 to 1.47) in KLoSA, and 1.65 (95%CI 1.31 to 2.07) in IFLS. However, with adjustment of potential confounders, the corresponding HRs dropped to 1.07 (95%CI 0.94 to 1.20) in ELSA, 1.08 (95%CI 0.97 to 1.22) in SHARE, 0.91 (95%CI 0.77 to 1.08) in KLoSA, and 0.89 (95%CI 0.66 to 1.21) in IFLS, respectively.

CONCLUSIONS

In these four population-based longitudinal studies, no association between symptomatic knee osteoarthritis and increased risk of all-cause mortality was observed after adjusting for potential confounders. Key Points • This study evaluated the association between symptomatic knee OA and the risk of all-cause mortality among the participants retrieved from four large population-based longitudinal studies across the world. • No association between symptomatic knee osteoarthritis and increased risk of all-cause mortality was observed after considering potential confounders, and our findings were consistent with the results derived from four independent longitudinal studies. • The present study included four international population-based longitudinal studies, comprising both developed and developing areas, which allowed the findings to be interpreted under larger circumstance.