Factors associated with neurokinin-1 receptor antagonist use among commercially insured cancer patients receiving highly emetogenic chemotherapy.

24 Background: Neurokinin-1 receptor antagonists (NK1RA) reduce chemotherapy-induced nausea/vomiting (CINV) among patients undergoing highly emetogenic chemotherapy (HEC). We evaluated factors associated with the use of NK1RA in patients treated with HEC. Methods: We performed a retrospective cohort study using Truven Health Marketscan to identify subjects who initiated HEC (doxorubicin or cisplatin) between 2009 and 2013, and concurrently received a NK1RA. Multivariable logistic regression was used, to determine the association of clinical and demographic factors and NK1RA use. Results: Of 32,004 subjects with cancer who were treated with either doxorubicin or cisplatin-containing regimens, 11,325 (33.3%) did not receive an NK1RA. From 2009 to 2013, NK1RA use increased from 53.2% to 73.5% (p < 0.0001). Compared to non-users, NK1RA users were more frequently treated with cisplatin-based regimens (67.9% vs. 32.1%, p < 0.0001), had in-network claims (66.7% vs. 33.3%, p < 0.0001), were younger, and without other comorbidities. Multivariate analysis demonstrated that NK1RA use was more likely with cisplatin compared to doxorubicin (OR = 1.71, 95% CI 1.62-1.81) and with female compared to male patients (OR = 1.75, 95% CI 1.65-1.84). In-network claims (OR 1.26, 95% CI 1.16-1.36) and comprehensive benefit plans (OR = 1.14, 95% CI 1.04-1.25) were associated with increased NK1RA use, compared to out-of network claims and preferred provider organizations (PPO), respectively. Age ≥ 65 years (OR = 0.64, 95% CI 0.5-0.69) and increased comorbidities (comorbidity score of 1: OR 0.88, 95% CI 0.83-0.94; score of 2- OR 0.61, 95% CI 0.56-0.67) versus a score of 0 were associated with decreased NK1RA use. Conclusions: A substantial proportion of patients receiving HEC do not receive NK1RA, and type of insurance coverage was associated with receipt.