S2085 Hospital-Acquired Clostridioides difficile Infection in Adult Oncology Patients: A Retrospective Nationwide Study of Risk Factors and Clinical Outcomes

Introduction: Clostridium difficile, a gram-positive anaerobic bacillus transmitted via the fecal-oral route, remains the leading cause of healthcare-associated infections. Emerging evidence highlights a disproportionately higher risk of C. difficile infection (CDI) among cancer patients, especially those with hematologic malignancies, due to their increased exposure to known risk factors. This study investigates the incidence, associated risk factors, and clinical outcomes of CDI among adult oncology patients across the United States. Methods: A retrospective cohort analysis was conducted using hospital data from the Nationwide Inpatient Sample (NIS) database from 2016-2022. Hospitalized adult cancer patients were identified using International Classification of Diseases, Tenth Revision codes. Baseline sociodemographic characteristics were compared between hospitalizations of cancer patients with and without CDI. Multivariable logistic regression analysis was used to identify factors associated with CDI. Results: Among 12,539,620 oncology hospitalizations included in the analysis, 39,620 (0.3%) were complicated by CDI. Patients who developed CDI were older (median age: 68 vs 67 years, P< 0.001), with a higher proportion ≥65 years (13,948; 35.2% vs 3,949,825; 31.6%; P = 0.017). Patients with CDI had longer hospital stays (median 12 vs 4 days), higher mortality (5.4% vs 0.9%), and greater costs (median $123,935 vs $42,555) compared to those without CDI (Pfor all < 0.001). Risk factors for CDI included Hispanic race (adjusted odds ratio [aOR] 1.83; P = 0.014), admission to large academic hospitals (aOR 1.19; P = 0.039), hospitals in the Midwestern US (aOR 1.39; P = 0.001), leukemia (aOR 1.15; P = 0.019), and pancytopenia (aOR 1.15; P = 0.028). Whereas mild or moderate loss of function were strongly protective in the multivariate model (aOR: 0.20 and 0.13, respectively; both P< 0.001), major mortality risk at admission (aOR 1.74, P = 0.013) and extreme mortality risk (aOR 3.84, P = 0.001) were correlated with greater CDI risk. Lung cancer (aOR 0.22), colorectal cancer (aOR 0.34), and Hodgkin's lymphoma (aOR 0.44) were associated with lower CDI risk. Conversely, lung/bronchus cancer (aOR 0.22, P < 0.001), colorectal cancer (aOR 0.34, P = 0.018), and Hodgkin’s lymphoma (aOR 0.44, P = 0.031) were all independently associated with lower odds. Conclusion: CDI is associated with substantial morbidity, mortality, and healthcare costs in hospitalized cancer patients. Targeted prevention strategies are needed for high-risk groups, including those with leukemia and critical illness.