Real-world Data on Risk Factors for Emergency Department Visits to Treat Outpatient Chemotherapy-Associated Toxicities.

The Centers for Medicare & Medicaid Services Hospital Outpatient Quality Reporting Program's OP-35 rule penalizes health systems that have a higher-than-expected rate of emergency department (ED) visits or inpatient admissions for 10 potentially preventable conditions within 30 days of receiving chemotherapy. Identifying patients at risk for toxicities and resultant acute care could lead to reducing the rate of such events, improving patient care, and reducing costs. We identified patients with cancer seen in the ED at our institution between January 1, 2018, and December 31, 2021, for one of the OP-35 toxicities who had received chemotherapy within the previous 30 days and analyzed demographic factors using zero-truncated Poisson regression. We further analyzed comorbid conditions for risk factors by matching by demographics and cancer type a cohort of patients without ED visits due to OP-35 events. A total of 1,618 patients were identified. The most frequent events were pain, sepsis, and fever. Thirty-nine percent had two or more visits during the study, and among those patients, the most frequent cancer types were gastrointestinal (32%) and breast (22%) cancers. Race, age, and sex were associated with an increased risk of events. In the matched cohort analysis, five comorbidities were statistically significant (P < 0.05) with event risk: history of coagulopathy/pulmonary emboli, myocardial infarction, cardiac arrhythmias, depression, and weight loss (concordance = 0.58). Forty-seven percent of patients with an event had at least one of these five comorbidities. Future interventions may concentrate on resources to monitor patients based on the risk assessment established in this study. SIGNIFICANCE: Cardiovascular comorbidities, cancer cachexia, and depression were associated with increased risk for ED visits due to OP-35 events throughout cancer treatment. Future interventions may concentrate on resources to monitor patients based on the risk assessment established in this real-world data study.