Global prevalence, incidence, and years lived with disability (YLDs) of osteoarthritis: trends from 1990 to 2021 and projections to 2050.

Background: To comprehensively assess the global burden of osteoarthritis (OA) from 1990 to 2021, analyze trends and patterns in its epidemiological shifts, and to project its changes through 2050. Methods: Data were extracted from the Global Burden of Disease Study 2021, including the numbers and age-standardized rates (ASRs) of prevalence, incidence, and years lived with disability (YLDs) of OA. We described OA epidemiology and trends by sex, age, anatomic site, high body mass index (BMI), sociodemographic index (SDI), and geographic regions, using estimated annual percentage changes (EAPCs), joinpoint regression analysis, and Age-period-cohort (APC) analysis. The OA burden was decomposed into contributions from aging, population size, and epidemiologic changes, and the changes of OA burden through 2050 were predicted by Bayesian APC (BAPC) model. Results: GBD 2021 estimated 607.0 million prevalent cases, 46.6 million incident cases, and 21.3 million YLDs of OA in 2021, with a globally increasing trend in overall burden observed from 1990 to 2021. The number of YLDs cases attributable to high BMI increased threefold, from 1.45 million in 1990 to 4.42 million in 2021. Joinpoint regression analysis indicated that the most pronounced increases were observed during 2006-2009 for prevalence, 2000-2009 for incidence, and 2006-2009 for YLDs. The risk of OA prevalence, incidence, and YLDs were influenced by age, period and cohort effect. Regarding the age effect, the relative risks for these outcomes initially increased and then declined. For the period effect, the relative risks increased by approximately 1.7-, 1.2-, and 1.7-fold for these outcomes. In the cohort effect, earlier-born cohorts demonstrated higher risks than their later-born counterparts. Results revealed that female individuals, knee OA, and middle SDI quintile were responsible for the most significant prevalence. The primary drivers of these changes were population growth and aging. Notably, the OA burden globally was predicted to increase from 2022 to 2050, with predicted values of 1.2 billion prevalent cases, 77.8 million incident cases, and 41.6 million YLDs by 2050. Conclusion: As a major global health issue, OA demonstrated a steady rise in global burden between 1990 and 2021, highlighting the pressing need for improved OA management strategies. This study offers valuable insights for policymakers in optimizing healthcare resource distribution and designs targeted interventions. The translational potential of this article: OA is a highly prevalent musculoskeletal disorder worldwide, with a globally increasing trend in its overall burden, imposing significant medical and economic challenges on both societies and individuals. Therefore, timely updates and comprehensive analyses of OA epidemiological data are crucial for the public, researchers, and healthcare policymakers. This study will contribute to the development of more effective OA management strategies and targeted interventions tailored to the specific needs and contexts of different regions and countries, with substantial translational potential.