Spatiotemporal distributions and regional disparities of rheumatoid arthritis in 953 global to local locations, 1980-2040, with deep learning-empowered forecasts and evaluation of interventional policies’ benefits

OBJECTIVES: To investigate global to local socioeconomic-driven distributions and inequalities in burdens of rheumatoid arthritis (RA) and to forecast long-term burdens. METHODS: We analysed the prevalence, incidence, mortality, disability-adjusted life years (DALYs), years of life lost (YLLs), and years lived with disability (YLDs) of RA across 953 locations worldwide, as well as their inequalities and ideal frontiers. A deep-learning pipeline was developed to forecast long-term burdens with scenario simulations. RESULTS: In 2021, RA affected 17.9 million people globally, with a 13.2% increase in incidence rate from 1990-2021, trending younger and broader. The age-standardised death rate fell 32.7% from 1980 to 2021, but global DALYs nearly doubled from 1990 to 2021. In 2021, among 652 subnational regions, West Berkshire in the UK had the highest age-standardised incidence rate (35.1; 95% uncertainty interval [UI]: 30.8-39.8). Zacatecas in Mexico had the highest age-standardised DALY rate (112.6; 95% UI: 87.2-142.7). Regions with a high sociodemographic index (SDI) bore the heaviest burden, with regional inequalities aggravating from 1990 to 2021. Over 90% of areas lagged in RA frontiers of multiple indicators. Japan uniquely showed declining trends (1990-2021), exemplified by Tokyo's age-standardised DALY rate dropping by 22.4% since 1990, unlike that in other high SDI regions. Implementing smoking control policies is forecasted to reduce RA-related deaths by 16.8% and DALYs by 20.6% among male patients in high-smoking regions like China. CONCLUSIONS: Demographic changes and uneven health infrastructure exacerbated RA burdens and disparities worldwide, with high SDI areas hardest hit while low SDI regions saw increases. Trend analysis empowered targeted policies such as localised smoking control to address these inequities.