A retrospective descriptive epidemiological study on global trends and disparities in the burden of osteoarthritis among adults aged ≥40 years: An age-stratified joinpoint regression analysis from 1990 to 2021.

ObjectiveOsteoarthritis (OA) is a leading cause of global disability, especially in aging populations. Comprehensive analyses of its long-term burden among adults aged ≥40 years are limited. This study aimed to assess global trends in OA burden from 1990 to 2021 to inform public health strategies.MethodsThis is a retrospective descriptive epidemiological study based on population-level aggregated public data. Using data from the Global Burden of Disease Study 2021, we estimated prevalence, incidence, and disability-adjusted life years (DALYs) for OA in adults aged ≥40 years. Age-standardized rates (ASRs) per 100,000 population were calculated. Joinpoint regression analysis was used to evaluate temporal trends. Analyses were stratified by age, sex, and socio-demographic index (SDI).ResultsIn 2021, the global prevalence of OA among adults aged ≥40 years was 6,967.3 per 100,000, with a significant increase since 1990 (AAPC=0.278). The burden was consistently higher in females, with a prevalence 39% greater than in males. The most rapid increase occurred in the 55-59 age group (AAPC=0.356). High body mass index was a major associated factor, associated with approximately 32.7% of prevalent cases in 2021 (AAPC for attributed DALYs=1.108). While high-income Asia Pacific had the highest prevalence (8,608.6 per 100,000), the fastest growth was observed in Southeast Asia (AAPC=0.545) and low-middle SDI regions.ConclusionThe global burden of OA continues to rise, with pronounced disparities by age, sex, and socioeconomic development. Our findings underscore the urgent need for early, targeted prevention strategies focusing on weight management and healthy aging to mitigate the future public health impact of OA.