Global, Regional and National Burden of Osteoarthritis, 1990-2021: A Decomposition and Age-Period-Cohort Analysis

Osteoarthritis (OA) is a leading cause of disability worldwide, driven by ageing populations and lifestyle factors, such as obesity and sedentary behaviours. Understanding the global, regional and national trends in OA prevalence is crucial for public health planning and resource allocation.

This study employed data from the Global Burden of Disease (GBD) 2021 database to examine the prevalence of OA from 1990 to 2021. Age-standardised prevalence rates (ASPR) and decomposition analysis were conducted to identify key drivers, including age structure shift, population growth and epidemiological change. An age-period-cohort (APC) model was applied to assess the influence of demographic shifts on OA prevalence. Stratified analyses were conducted by socio-demographic index (SDI) regions to assess disparities in OA burden.

The global number of OA cases rose from 256 million (95% CI: 227-283 million) in 1990 to 607 million (95% CI: 538-671 million) in 2021, with an ASPR of 6967.29 (95% CI: 6180.70-7686.06) per 100,000 individuals. Population growth contributed 74% of this increase, whereas age structure shift accounted for 16%. High SDI regions reported the highest ASPR, with 7897.27 (95% CI: 7067.13-8689.88) per 100,000, compared with 5605.58 (95% CI: 4967.54-6230.60) in low SDI regions.

The global burden of OA has escalated during the last 30 years, particularly in ageing populations. Although population growth and demographic shifts are major drivers, regional disparities highlight the need for targeted prevention strategies and improved healthcare access in lower SDI regions.