Investigating rates of CINV across settings of care in Medicare: A retrospective claims-based analysis.

Abstract

297 Background: Clinical practice may differ according to settings of care and may impact both the quality of care delivered and, ultimately, patient outcomes. This study describes the differences in chemotherapy-induced nausea and vomiting (CINV) rates between chemotherapy (CT) naïve Medicare cancer patients starting CT in a hospital outpatient (HOP) or community outpatient (COP) setting. Methods: Using the 5% Medicare Fee-for-Service standard analytic files, patients with a new claim of CT and ≥1 outpatient cancer diagnosis claim between 1/1/10 – 6/30/11 were identified. Patients with a previous inpatient cancer diagnosis, multi-day CT cycles or who switched CT relevant to emetogenic potential were excluded. CINV was defined using relevant claims-based ICD-9-CM diagnosis and procedure codes within days 2-7 of the first 8 single-day CT cycles or the first 6 months following the index CT claim. CINV events were evaluated descriptively and using regression models. Results: Medicare patients receiving CT in HOP (n=1,007) vs. COP (n=1,080) were similar in demographics such as age, race, and baseline healthcare costs. However, Medicare patients receiving CT in COP compared to those in HOP settings were more likely to be female (57.0% vs. 44.7%), breast cancer patients (27.6% vs. 16.0%), live in the South region (37.7% vs. 32.3%), have higher Charlson Comorbidity Index scores (mean 5.2 vs. 4.8) and receive moderately to highly emetogenic CT (44.1% vs. 36.0%) (all p<0.05). Overall, 13.9% had any CINV in the evaluation period. More CINV events per patient were reported among those in COP compared to those in HOP settings (0.43 vs 0.27, p <0.05). However, differences between settings of care were not shown to be significantly different in adjusted regression analyses (p=0.177). Conclusions: We found the population characteristics between Medicare patients treated with CT in HOP and COP to vary on a number of factors. However, after controlling for these differences, our results suggest the number of CINV events was similar across settings of care. Future research should further clarify how differences in quality of care for antiemesis between COP and HOP settings may impact the incidence of CINV events in this population.