Confirming the association of ulcerative colitis with interstitial lung disease: a retrospective analysis of comorbid disease, demographics, and healthcare utilization.

BACKGROUND: Interstitial lung disease (ILD) is a rare extraintestinal manifestation associated with inflammatory bowel disease (IBD). Limited information is available regarding the prevalence and risk factors of ILD in IBD. This study aimed to determine the association of ILD in Crohn's disease (CD) and ulcerative colitis (UC), while analyzing various contributory factors. METHODS: A retrospective analysis of patient data at two major tertiary healthcare centers in the southeastern United States from 2012 to 2022 was conducted. Patient demographics, healthcare utilization patterns, and coexisting diagnoses of IBD and ILD were analyzed using comparative statistical analysis. RESULTS: A total of 8865 IBD patients were included in the study, of which 408 (4.6%) had concomitant IBD and ILD. Patients with UC had a significantly higher prevalence of ILD compared to those with CD (P < .001). There were no statistically significant differences in demographics between UC-ILD and CD-ILD patients. There was a significant difference in prevalence between White patients and minority patients with IBD and any form of ILD (P < .001). Finally, individuals with IBD-ILD were significantly older, had a higher proportion of emergency department (ED) visits, had a higher proportion of hospitalizations, had a higher proportion of patients with steroid use, and had a lower proportion of patients with mesalamine prescribed (P < .001), compared with IBD-only patients. CONCLUSIONS: Our findings confirm the established literature that ILD is more associated with UC compared to CD, while providing new insight into demographic and healthcare utilization factors between CD-ILD and UC-ILD patients and between IBD-ILD compared to IBD-only patients.