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

Abstract

Objectives: We aim to investigate the contribution of Interstitial Lung Disease (ILD) to mortality in patients with Inflammatory Bowel Disease (IBD). Methods: We carried out a comprehensive retrospective, population-based epidemiological study across the United States from 2001 to 2020, using the Wide-ranging Online Data for Epidemiologic Research (WONDER) 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 (CD), and K51 for Ulcerative Colitis (UC). To discern patterns, Age-adjusted Mortality Rates (AMR) were computed, stratified by gender, geographic census region, and racial/ethnic demographics. Results: From 2001 to 2020, there were 57,967 reported deaths among IBD patients 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 two decades. ILD was a more common cause of death in patients with CD than with UC (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). Conclusions: 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.