Global, regional and national burden of rheumatoid arthritis from 1990 to 2021, with projections of incidence to 2050: a systematic and comprehensive analysis of the Global Burden of Disease study 2021

Abstract Background To provide insights into rheumatoid arthritis (RA) epidemiological trends, including prevalence, incidence, disability-adjusted life years (DALYs), corresponding average annual percentage change (AAPC), gender disparities, regional variations, age-specific rates, socio-economic correlations, risk factors, and future projections. Methods Data were extracted from the Global Burden of Disease Study (GBD) 2021. AAPC was calculated by joinpoint regression and two-sample Mendelian randomization (MR) analysis was performed to verify the causal relationship between the smoking factor and RA. The future incidence trend was predicted by the Bayesian age-period-cohort (BAPC) model. Results Global age-standardized prevalence rate (ASPR) and age-standardized incidence rate (ASIR) increased significantly while age-standardized DALYs rate (ASDR) decreased from 1990 to 2021. Regional variations were pronounced, with Andean Latin America reporting the highest burden. Females consistently exhibited higher age-standardized rate (ASR) across all metrics. Age-specific prevalence, incidence, and DALYs rates peaked at different age groups, highlighting complex demographic dynamics. Socio-demographic index (SDI) analysis demonstrated a positive correlation between RA burden and socio-economic development. The two-sample MR analysis confirmed a causal effect between smoking and RA. From 2022 to 2050, the ASIR will increase moderately. Conclusions The study underscores the escalating burden of RA globally, emphasizing the need for healthcare providers to be aware of the effects of aging populations and other societal factors on the risk of developing RA, and to develop targeted interventions, including smoking cessation programs, age- and gender-appropriate healthcare, and early diagnosis strategies.