Outcomes of

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with poor prognosis. Patients with IPF are frequently exposed to risk factors for Methods: We conducted a retrospective cohort study using the National Inpatient Sample (2016-2020) to compare outcomes among hospitalized CDI adults with or without IPF as a pre-existing comorbidity. Hospitalizations were identified using ICD-10 codes. Propensity score matching (1:4) was performed to balance demographics and comorbidities. The primary outcome was all-cause in-hospital mortality; secondary outcomes included length of stay, hospitalization costs, mechanical ventilation, vasopressor use, and major adverse events. Results: Of 1 450 860 CDI hospitalizations, 1600 (0.11%) had IPF. After matching, IPF was independently associated with higher in-hospital mortality (aOR 1.85, 95% CI 1.22-2.76), longer hospital stays, and increased hospitalization costs. IPF patients were more likely to require mechanical ventilation (aOR 1.79, 95% CI 1.27-2.52). However, rates of fulminant CDI complications (severe sepsis, toxic megacolon, ileus, colectomy, ileostomy) were not significantly increased in the IPF cohort after matching. Conclusions: Hospitalized CDI patients with IPF experience significantly higher mortality and resource utilization compared to those without IPF. The absence of increased fulminant CDI complications suggests that CDI may act as a marker of underlying disease severity in IPF rather than a direct cause of death. These findings highlight the need for risk stratification in CDI patients with chronic lung diseases.