Interstitial Lung Disease as an Emerging Contributor to Mortality in Patients With Inflammatory Bowel Disease: A Population-Based Epidemiological Study.

Introduction: We aim to investigate the contribution of interstitial lung disease (ILD) to mortality in patients with inflammatory bowel disease (IBD).

Methods: We performed a comprehensive retrospective, population-based epidemiological study across the United States from 2001 to 2020, using the Wide-ranging Online Data for Epidemiologic Research database. Mortality data were classified according to the International Classification of Diseases, Tenth Revision , with the codes J84 for ILD, K50 for Crohn's disease, and K51 for ulcerative colitis. To discern patterns, age-adjusted mortality rates (AMR) were computed, stratified by sex, geographic census region, and racial/ethnic demographics.

Results: From 2001 to 2020, there were 57,967 reported deaths among patients with IBD with an AMR per million significantly rising from 10.989 in 2001-2005 to 11.443 in 2016-2020 ( P < 0.0001). ILD was a contributor to death in 1.19% (692/57,967) of these cases, with AMR rising from 0.092 to 0.143 per million ( P = 0.010). The percentage of ILD-related deaths in the IBD population increased from 1.02% to 1.30% over 2 decades. ILD was a more common cause of death in patients with Crohn's disease than with ulcerative colitis (54.6% vs 45.4%), with a significant increase for both conditions from 2001 to 2020 ( P < 0.05). An upward trend in ILD-related mortality was observed in both sexes ( P < 0.05) and within the White population ( P = 0.010).

Discussion: The observed increase in mortality rates due to ILD among patients with IBD is concerning and highlights a critical need for systematic ILD screening protocols within the IBD patient population to facilitate early detection and management.