Epidemiology of Rheumatoid Arthritis in the Asia-Pacific Region: A Systematic Analysis of the Global Burden of Disease Study 1990-2023 and Forecasts to 2025.

Abstract

Updated, country-specific burden curves for rheumatoid arthritis (RA) across the Asia-Pacific region remain limited. We aimed to quantify long-term trends in RA prevalence, incidence, mortality, and disability-adjusted life-years (DALYs) from 1990 to 2023, and to project short-term burden to 2025. We extracted age-standardized rates (ASRs) and absolute counts for rheumatoid arthritis from the Global Burden of Disease (GBD) 2023 study for 27 Asia-Pacific countries and territories. Temporal trends were summarized using average annual percent change (AAPC) estimated from joinpoint regression, and short-term projections to 2025 were generated using Bayesian age-period-cohort models. Decomposition analysis quantified the relative contributions of population aging, population growth, and changes in age-specific rates to observed increases in prevalent cases. Between 1990 and 2023, the regional age-standardized prevalence rate of rheumatoid arthritis increased by approximately 16%, reaching 126 per 100 000 population in 2023, and is projected to rise further to 131 per 100 000 (95% uncertainty interval [UI] 124-138) by 2025. Age-standardized incidence increased from 10.0 to 11.6 per 100 000, with a projected rate of 12.1 per 100 000 (95% UI 11.2-13.0) in 2025. In contrast, age-standardized mortality declined by 43% (from 0.75 to 0.43 per 100 000), and DALY rates decreased modestly (from 45.3 to 41.8 per 100 000), although absolute DALYs increased due to demographic expansion. Decomposition analysis indicated that 84% of the net increase in prevalent RA cases was attributable to population aging and growth, with only 16% associated with rising age-specific prevalence rates. Female-to-male prevalence ratios remained stable at approximately 2.3-2.4 throughout the study period. The fastest relative increases were observed in lower-middle-income South-East Asian countries, while several high-income Western-Pacific countries showed stable or declining rates. The expanding burden of rheumatoid arthritis in the Asia-Pacific region is driven predominantly by demographic momentum rather than worsening per-capita risk. Although mortality and per-capita disability are declining, absolute health loss will continue to rise under population aging. Integrating early RA care with population-level prevention targeting modifiable risk factors may mitigate future burden growth.