Impact of provider volume on front-line chemotherapy guideline compliance and overall survival in elderly patients with advanced ovarian cancer.

ABSTRACT

PURPOSE: We sought to evaluate whether provider volume or other factors are associated with chemotherapy guideline compliance in elderly patients with epithelial ovarian cancer (EOC). METHODS: We queried the SEER-Medicare database for patients ≥66 years, diagnosed with FIGO stage II-IV EOC from 2004 to 2013 who underwent surgery and received chemotherapy within 7 months of diagnosis. We compared NCCN guideline compliance (6 cycles of platinum-based doublet) and chemotherapy-related toxicities across provider volume tertiles. Factors associated with guideline compliance and chemotherapy-related toxicities were assessed using logistic regression. Overall survival (OS) was compared across volume tertiles and Cox proportional-hazards model was created to adjust for case-mix. RESULTS: 1924 patients met inclusion criteria. The overall rate of guideline compliance was 70.3% with a significant association between provider volume and compliance (64.5% for low-volume, 72.2% for medium-volume, 71.7% for high-volume, p = .02). In the multivariate model, treatment by low-volume providers and patient age ≥ 80 years were independently associated with worse chemotherapy-guideline compliance. In the survival analysis, there was a significant difference in median OS across provider volume tertiles with median survival of 32.8 months (95%CI 29.6, 36.4) low-volume, 41.9 months (95%CI 37.5, 46.7) medium-volume, 42.1 months (95%CI 38.8, 44.2) high-volume providers, respectively (p < .01). After adjusting for case-mix, low-volume providers were independently associated with higher rates of mortality (aHR 1.25, 95%CI 1.08, 1.43). CONCLUSIONS: In a modern cohort of elderly Medicare patients with advanced EOC, we found higher rates of non-compliant care and worse survival associated with treatment by low-volume Medicare providers. Urgent efforts are needed to address this volume-outcomes disparity.