Patient factors and costs associated with prophylactic neurokinin-1 receptor antagonist use among women with invasive breast cancer.

Abstract

In April 2012, the American Society of Clinical Oncology joined the Choosing Wisely (CW) initiative to reduce the use of low-value oncology services. Neurokinin-1 receptor antagonists (NK1-RAs) are a class of expensive antiemetic drugs and are not recommended for patients who receive low to moderate risk emetogenic anticancer agents. To identify patient factors and costs associated with NK1-RAs prophylactic use in a real- world setting post-Choosing Wisely among patients with breast cancer. Using Optum's de-identified Clinformatics^® Data Mart Database (2013 to 2018), a retrospective cohort study was conducted for women aged 18 years and older with breast cancer who initiated a low/minimal/moderate emetogenic chemotherapy (index date) and received prophylactic antiemetics 2 weeks prior to the index date through the day after index (N = 18,515). Patients with no claims for antiemetics or who had negative costs were excluded from the costs analysis (n = 12,068). All US Food and Drug Administration-approved NK1-RAs were included. A multivariable logistic regression model was used to assess the association between patient demographic and socioeconomic characteristics, health system and environmental factors, and NK1-RA use, with results presented as adjusted odds ratios (AORs) and 95% CIs. A generalized linear model with gamma distribution and log link and two-part model were used to model mean third-party and out-of-pocket antiemetic-specific costs per patient, respectively, controlling for baseline patient characteristics. Out of 18,515 women included, 7.7% (n = 1,429) received NK1-RAs. As compared with women aged 75 years and older, those aged 50-64 and 65-74 years had 1.96 (95% Cl = 1.50-2.57) and 1.39 (95% Cl = 1.19-1.63) times higher odds to receive NK1-RAs, respectively. Black women (AOR: 1.35; 95% Cl = 1.12-1.63), intravenous low-emetogenic chemotherapy (AOR: 3.94; 95% Cl = 3.16-4.91), enrolled in Medicare low-income subsidy (AOR: 1.49; 95% Cl = 1.08-2.07), had higher odds of receiving prophylactic NK1-RAs as compared with White patients, intravenous moderate emetic risk chemotherapy, and commercial insurance, respectively. In the adjusted analysis for costs, the mean total third-party payer antiemetic-specific costs for women who received steroids only, first-generation serotonin-receptor antagonists (5HT3-RAs) with or without steroids, or second-generation 5HT3-RAs with or without steroids were found to be significantly lower by 97.8% (<i>P</i> < 0.001), 95.0% (<i>P</i> < 0.001), and 42.1% (<i>P</i> = 0.023), respectively, when compared with those who received NK1-RAs. Variability in the potential overuse of NK1-RAs was driven by certain patient- (age, race and ethnicity), clinical- (emetic risk), and health care- (insurance, health plan type) related factors. Furthermore, the mean total costs reimbursed by payers were significantly higher for those who received NK1-RAs as compared with other antiemetics, except for those who received both first- and second-generation 5HT3-RAs with or without steroids. Guideline-concordant use of NK1-RAs could result in significant cost-avoidance for patients and payers.