Regional disparities, age-related changes and sex-related differences in knee osteoarthritis

Background The objective of the study is to analyse the regions, age and sex differences in the incidence of knee osteoarthritis (KOA). Methods Data were extracted from the global burden of diseases (GBD) 2019 study, including incidence, years lived with disability (YLD), disability-adjusted life-years (DALYs) and risk factors. Estimated annual percentage changes (EAPCs) were calculated to quantify the temporal trends in age standardized rate (ASR) of KOA. Paired t-test, paired Wilcoxon signed-rank test and spearman correlation were performed to analyze the association of sex disparity in KOA and socio-demographic index (SDI). Results There were significant regional differences in the incidence of knee osteoarthritis. In 2019, South Korea had the highest incidence of knee osteoarthritis (474.85,95%UI:413.34–539.64) and Thailand had the highest increase in incidence of knee osteoarthritis (EAPC = 0.56, 95%CI = 0.54–0.58). Notably, higher incidence, YLD and DALYs of knee osteoarthritis were associated with areas with a high socio-demographic index ( r = 0.336, p < 0.001; r = 0.324, p < 0.001; r = 0.324, p < 0.001). In terms of age differences, the greatest increase in the incidence of knee osteoarthritis was between the 35–39 and 40–44 age groups. (EAPC = 0.52, 95%CI = 0.40–0.63; 0.47, 95%CI = 0.36–0.58). In addition, there were significant sex differences in the disease burden of knee osteoarthritis ( P < 0.001). Conclusions The incidence of knee osteoarthritis is significantly different with regions, age and sex.