The prevalence of symptomatic knee osteoarthritis in China: Results from China Health and Retirement Longitudinal Study

Objective : To estimate the prevalence of symptomatic knee osteoarthritis (SxOA) in China. Methods : Using data collected from the China Health and Retirement Longitudinal Study (CHARLS), a population-based longitudinal survey conducted between 2011 and 2012, we estimated the prevalence of SxOA by sex, age, rural/urban area, socio-economic status and geographic region. Results : Of 17128 individuals (mean age: 59.8 years; women: 51.6%) included in the analysis, 1591 (8.1%) had knee SxOA. Prevalence of knee SxOA was higher in women (10.3%) than that in men (5.7%), with an adjusted odds ratio (OR)=1.88 (95% confidence interval (CI): 1.64-2.17). Knee SxOA prevalence increased with age (P for trend?<?0.01). SxOA was more common in rural than that in urban areas (OR=1.84, 95% CI: 1.46-2.31). Individuals who received more years of education and who lived in more developed areas had lower prevalence of knee SxOA (P for trend?<?0.01). Individuals living in the North and East regions of China had the lowest prevalence of knee SxOA (5.4% and 5.5%), followed by those in the North-East (7.0%), South-Central (7.8%), North-West (10.8%), and the South-West regions (13.7%), respectively. Conclusion : Knee SxOA in China was prevalent and prevalence varied according to socio-demographic, economic and geographic factors. Epidemiologic studies of identifying risk factors that are attributable to the variation of prevalence in knee SxOA in China are warranted. This article is protected by copyright. All rights reserved