Provider‐ and patient‐level predictors of oral anticancer agent initiation and adherence in patients with metastatic renal cell carcinoma

BACKGROUND: Improving oral anticancer agent (OAA) initiation and adherence is the important quality‐of‐care issues, particularly since one fourth of anticancer agents being developed will be administered orally. Our objective was to identify provider‐ and patient‐level characteristics associated with OAA initiation and adherence among individuals with metastatic renal cell carcinoma (mRCC). METHODS: We used state cancer registry data linked to multi‐payer claims data to identify patients with mRCC diagnosed in 2004–2015. Provider data were obtained from North Carolina Health Professions Data System and the National Plan & Provider Enumeration System. We estimated risk ratios (RRs) and corresponding 95% confidence limits (CLs) using modified Poisson regression to evaluate factors associated with OAA initiation and adherence. RESULTS: Among the 207 (out of 687) patients who initiated an OAA following mRCC diagnosis and survived 90 days, median proportion of days covered was 0.91. Patients with a modal provider specializing in hematology/medical oncology were much more likely to initiate OAAs than those seen by other specialties. Additionally, patients with a female provider were more likely to initiate OAAs than those with a male provider. Compared to patients treated by providers practicing in both urban and rural areas, patients with providers practicing solely in urban areas were more likely to initiate OAAs, after controlling for patient‐level factors (RR = 1.37; 95% CL: 1.09–1.73). Medicare patients were less likely to be adherent than those with private insurance (RR = 0.61; 95% CL: 0.42–0.87). CONCLUSIONS: Our results suggest that provider‐ and patient‐level factors influence OAA initiation in patients with mRCC but only insurance type was associated with adherence.