Assessing the Global Burden of Interstitial Lung Disease and Pulmonary Sarcoidosis Using Multiple Statistical Models: Analysis and Future Projections

Background Interstitial lung disease (ILD) and pulmonary sarcoidosis (PS) represent significant global health challenges, characterized by progressive respiratory symptoms and heterogeneous epidemiological trends. Despite rising incidence and mortality rates post-COVID-19, research on their burden and risk factors remains limited. This study aims to elucidate the spatiotemporal distribution, gender/age disparities, and sociodemographic drivers of ILD and PS from 1990 to 2021, providing evidence for targeted interventions. Methods Utilizing data from the Global Burden of Disease (GBD) 2021, we analyzed age-standardized incidence (ASIR), mortality (ASMR), and disability-adjusted life years (ASDR) across 204 countries/regions. Temporal trends were assessed using average annual percentage change (AAPC), age-period-cohort (APC), and Bayesian APC (BAPC) models. Decomposition and Pearson correlation analyses evaluated the roles of aging, population growth, and sociodemographic index (SDI). Joinpoint regression identified inflection points in trends. Future disease burdens (2021–2050) were projected via BAPC modeling. Results Globally, ILD and PS cases surged from 157,441.17 (1990) to 390,267.11 (2021), with ASIR, ASMR, and ASDR increasing annually by 0.61%, 1.32%, and 0.83%, respectively. High-SDI regions exhibited the highest ASIR (71.4/100,000) and ASMR (25.5/100,000). Males had higher burdens than females (DALYs: 2,237,269 vs. 1,804,881 in 2021), with peaks in the 70–74 age group. SDI correlated positively with ASIR and ASMR, showing a U-shaped relationship in some regions. Projections indicated stable ASMR but rising ASIR and ASDR by 2050, particularly among males. Conclusions The global burden of ILD and PS has risen significantly since 1990, driven by aging, industrialization, and socioeconomic disparities. Prioritizing early screening (e.g., HRCT, serum biomarkers), reducing environmental/occupational exposures, and implementing gender/age-specific interventions are critical. Strengthening healthcare infrastructure in low-SDI regions and integrating advanced diagnostic technologies are essential to mitigate future burdens.