LAUSR

e18625 Background: In clinical oncology practice, diarrhea is a very common and severe side effect of cancer treatments including from radiotherapy, chemotherapy, and targeted therapies. Cancer-related diarrhea (CRD) leads to increased healthcare resource consumption due to unscheduled outpatient visits, and , increased hospital stays requiring intensive supportive care measures. We evaluated CRD patients receiving chemotherapy, targeted therapy, or both, requiring emergency department (ED), physician office visits, hospitalizations, and length of stay (LOS) compared to a matched cohort of non-CRD patients. Methods: We performed a longitudinal study among adult patients ( > 18 yrs) with CRD identified by diagnosis codes or pharmacy claims compared to matched non-CRD patients using claims data derived from the IQVIA PharMetrics Plus database. Index date was the first cancer claim date and patients were re-indexed based on their CRD claim. Each patient had a 6-month pre-index period, a minimum 3-month post-index period and had ≥12 months of continuous enrollment following the CRD index date. To adjust for selection bias and baseline differences, we matched CRD patients to non-CRD patients (1:1) by age, gender, geography and payer type. Patients were stratified by cancer therapy type (chemotherapy, targeted therapy or both treatments). We reported proportion of patients with hospitalizations, average length of stay (LOS), and ED visits. A generalized estimating equation model with log link and binomial distribution adjusted for type of cancer, therapy, and Charlson Comorbidity Index (CCI) was built to estimate the difference in occurrence of hospitalization between CRD and non-CRD cohorts. Results: We evaluated a total of 104,135 matched pairs of CRD and non-CRD adult patients with solid or hematologic cancer with 12-month continuous enrollment. The proportion of patients with ED visits (36.2% vs 18.9%, p < 0.0001) and hospitalizations (29.6% vs 12.8%, p < 0.0001) were significantly higher among CRD versus non-CRD cohort. When compared to non-CRD patients, CRD patients were more likely to be hospitalized (adjusted OR 2.28. 95% CI of 2.23-2.33). Mean CRD-specific office/hospital visits were significantly higher in the CRD cohort compared to the non-CRD cohort over the 12-month post-index period and patients had more CRD-specific visits to ED (7.5% vs 1.8%); physician’s offices (14.7% vs 3.8%); laboratory testing (11.6% vs 3.2%) and outpatient ancillary services (10.9% vs 2.6%) (all p < 0.0001). Mean hospital LOS among patients with CRD was higher than non-CRD patients (6.6±8.9 vs 5.8±10.5 days, p < 0.0001). Conclusions: Patients with CRD used significantly more resources, including outpatient services, ED visits, and hospitalizations. Effective prevention of CRD remains an unmet strategy to reduce the overall cost of cancer care.