Global, regional, and national epidemiology of rheumatoid arthritis among people aged 20–54 years from 1990 to 2021

Rheumatoid arthritis (RA) is a global epidemic. We conducted a cross-sectional study using the Global Burden of Disease (GBD) 2021 dataset to examine RA trends in patients aged 20-54 years worldwide. Key outcomes included incidence, mortality, and disability-adjusted life years (DALYs), as well as trends over time, stratifying by region, country, age, sex, and Sociodemographic Index (SDI). We also assessed the contribution of smoking to RA-related mortality and DALYs. Over the past 32 years, the global RA-related incidence rate increased from 11.66 (95% UI 9.60-13.94) to 13.48 (95% UI 11.08-16.06) per 100,000 population. RA-related DALYs rate increased from 26.37 (95% UI 18.43-36.99) to 30.71 (95% UI 20.82-44.08) per 100,000 population, with females bearing a higher burden. And the RA-related mortality rate decreased from 0.09 (95% UI 0.08-0.1) to 0.06 (95% UI 0.05-0.07) per 100,000 population. Regional disparities were evident, with lower SDI regions experiencing the larger change. Smoking remained a significant risk factor, accounting for 9.01% of RA-related mortality in 2021. Overall, we highlighted the rising global burden of RA, particularly among females and in lower SDI regions, emphasizing disparities in healthcare resources, prevention, and early diagnosis.