Symptomatic Knee Osteoarthritis is the Third Most Prevalent Cause of Catastrophic Health Expenditure for Chinese People: A Nationally Representative Panel Data Analysis Based On The China Health and Retirement Longitudinal Study

Background: This study examined the distribution of symptomatic knee osteoarthritis (SKOA) according to sociodemographic characteristics and its association with the utilization of healthcare service and catastrophic health expenditure. It compared the effect of 14 common chronic diseases on healthcare usage and spending.Methods: We used the data from three waves (2011, 2015, 2018) of the China Health and Retirement Longitudinal Study (CHARLS). Participants aged 45 and over in 2011 were included in this study. We used catastrophic health expenditure as the index for health spending.Findings: The baseline survey of CHARLS comprised 17,708 participants, and 9,660 were eligible for inclusion. In 2018, the participants’ median age was 64 years (IQR, 58–70); 48·1% were men; and the overall SKOA prevalence was 30·3% (weighted prevalence, 28·5%). SKOA prevalence increased with age and was higher in women, higher socio-economic groups, and rural areas. SKOA was most common in western China. It was associated with increased outpatient visits (incidence rate ratio, 1·62; 95% confidence interval, 1·51–1·74) and inpatient hospital stay (1·75, 1·62–1·90), and a significantly increased probability of catastrophic health expenditure (odds ratio,,1·64; 95% CI, 1·49–1·81), with its effect persisting even among higher socio-economic groups.Interpretation: Concerted efforts are needed to develop early prevention measures and screening methods for SKOA, especially for middle-aged people.Funding Information: None.Declaration of Interests: We declare no competing interests.Ethics Approval Statement: The CHARLS study was approved by the Biomedical Ethics Review Committee of Peking University (approval number: IRB00001052-11015), and all of the participants signed informed consent forms.