Patient- and provider-level predictors of mortality among patients with metastatic renal cell carcinoma receiving oral anticancer agents.

Abstract

116 Background: It is important to understand how emerging new therapies, such as oral anti-cancer agents (OAAs), diffuse across and can improve outcomes within real-world populations, which include age groups and racial groups not well-represented in clinical trials, such as people older than age 65 and Black patients. Our objectives were to examine whether disparities in mortality persist among patients with metastatic renal cell carcinoma (mRCC) receiving OAAs and whether these disparities may be partially explained by patient’s clinical characteristics or provider-level factors. Methods: We used linked state cancer registry data and multi-payer claims data to identify patients with mRCC who were diagnosed in 2004 through 2015 and had initiated an OAA and survived ≥ 90 days after initiating. Provider data were obtained from North Carolina Health Professions Data System and the National Plan & Provider Enumeration System. A patient’s modal provider was the provider most frequently on claims with a diagnosis code of RCC or metastatic cancer between 2 months prior to and 3 months following the index date. We estimated hazard ratios (HR) and corresponding 95% confidence limits (CL) using Cox proportional hazard models to evaluate which patient demographics, patient clinical characteristics, and provider-level factors were associated with 2-year all-cause mortality. Results: The cohort included 207 patients with mRCC. In unadjusted analyses, public insurance (Medicaid or Medicare), de novo metastatic diagnosis, frailty, polypharmacy, and a visit to a skilled nursing facility were associated with increased all-cause mortality. In multivariable models, clinical variables such as frailty (HR: 1.36, 95% CL: 1.11-1.67) and de novo metastatic diagnosis (HR: 2.63, 95%CL: 1.67-4.16) were associated with higher all-cause mortality. Additionally, Medicare-insured patients continued to have higher all-cause mortality compared to privately insured patients (HR: 2.35, 95% CL: 1.32-4.18). None of the provider-level covariates (i.e., specialization, experience, volume, or practice location) investigated were associated with all-cause mortality. Conclusions: Even when adjusting for age, frailty, and comorbidities, Medicare-insured patient had lower overall survival than privately-insured patients. Patient survival did not differ based on modal provider’s characteristics.