OP-35: Does a tool designed to measure potentially preventable chemotherapy toxicities do so effectively?

1538 Background: OP-35 is a measure developed by the National Quality Foundation that the Center for Medicare and Medicaid Services (CMS) uses to evaluate the quality of care for patients undergoing outpatient chemotherapy treatment. Launched in 2021, it was intended to measure rates of potentially preventable complications of chemotherapy treatment. The tool assesses the rate of emergency department visits and admissions (EDV/A) visits for patients receiving outpatient intravenous (IV) systemic anti-cancer therapy (SACT) and defines potentially preventable by the presence of ≥1 of 10 diagnoses: anemia, dehydration, diarrhea, emesis, fever, nausea, neutropenia, pain, pneumonia, or sepsis. However, it is unknown if these diagnoses track truly preventable visits and therefore if it is a valid measure of quality. Methods: We conducted a retrospective review of patients who received outpatient IV SACT (the denominator for OP-35) at the University of Texas MD Anderson Cancer Center between January 2023 and December 2023. All patients who had an EDV/A were assessed to understand the primary and secondary diagnoses associated with their encounters. Results: The total number of patients included in the population who received outpatient IV SACT was 10,353. Of these, 2,401 (23.2%) had an EDV/A within 30 days of receiving outpatient IV SACT. Of patients with an EDV/A, 67% of patients had one EDV/A, 21% had 2, and 12% had ≥3. The most common diagnosis groups were pain (83%), anemia (69%), nausea (44%), and fever (35%). 82% of patients had more than one qualifying diagnosis. For 68%, the qualifying diagnosis was a secondary diagnosis. Of patients with a qualifying EDV/A, only 15% did not have a qualifying OP-35 diagnosis. Conclusions: While OP-35 was designed to measure potentially preventable chemotherapy-related complications, the exclusion of relatively few patients among those with an EDV/A suggests that a significant proportion of qualifying events may not truly be preventable. The qualifying diagnosis list may need to be tailored to exclude non-preventable admissions. This would improve the metric’s specificity and validity as measure of care-quality. Future work should clarify which diagnoses lead to misclassification of non-preventable EDV/As. Patients with qualifying EDV/A N = 2,401 Type of Cancer Solid Malignancy 2,020 (84%)* Heme Malignancy 383 (16%)* Qualifying OP-35 Diagnosis Pain 1,998 (83%) Anemia 1,652 (69%) Nausea 1,065(44%) Fever 833 (35%) Dehydration 679 (28%) Pneumonia 552 (23%) Neutropenia 509 (21%) Diarrhea 534 (22%) Sepsis 364 (15%) Emesis 148 (6%) Number of EDV/A Per Patient 1 1,614 (67%) 2 502 (21%) ≥3 285 (12%) *Two patients categorized with both solid and heme malignancies.