Age-standardised prevalence, incidence and mortality rates of interstitial lung disease and pulmonary sarcoidosis in Saudi Arabia, 1990–2023: a GBD-based population analysis

Introduction: Interstitial lung disease and pulmonary sarcoidosis are increasingly recognised worldwide, yet population-level epidemiological data from Saudi Arabia remain scarce. Theory: This analysis is framed within the Global Burden of Disease (GBD) framework, in which these conditions form a predefined combined cause category within a mutually exclusive cause hierarchy. GBD outputs are modelled estimates, so temporal change may reflect diagnostic capacity, coding practices and data availability as well as underlying disease occurrence. Method: Data were extracted from GBD 2023 for Saudi Arabia (location ID 152, cause ID 516). Age-standardised rates per 100,000 population with 95% uncertainty intervals were analysed by sex and age group using Joinpoint regression, age–period–cohort analysis, and ARIMA forecasting. Results: Between 1990 and 2023, prevalence increased from 50.33 to 79.90 per 100,000 in males and from 76.52 to 115.28 in females. Incidence increased from 5.86 to 8.64 and from 7.28 to 10.81, and mortality from 3.43 to 5.43 and from 3.05 to 7.88. Average annual percent changes were +1.41% in males and +1.25% in females for prevalence, +1.18% and +1.20% for incidence, and +1.40% and +2.92% for mortality. Discussion: GBD-modelled estimates suggest an increase in the estimated burden, with higher female prevalence and incidence estimates, a female-to-male mortality ratio that increased over time, and a strong age-related pattern. Findings should be interpreted cautiously, as temporal change may reflect diagnostic capacity, coding practices, healthcare access, data availability and modelling assumptions. Improved national disease monitoring, registry development and primary epidemiological studies are needed.