OBJECTIVES: As a part of the Choosing Wisely (CW) campaign aimed at reducing low-value services, the American Society of Clinical Oncology (ASCO) recommends against the use of expensive antiemetics in patients receiving a low-to-moderate emetic risk chemotherapy regimen. The objective of the study was to identify predictors of NK1-RA overuse during the post-CW era, among women with breast cancer.

METHODS: A retrospective cohort study was conducted using Optum’s de-identified Clinformatics® Data Mart Database (2010-2018). Women aged ≥18 years with breast cancer, with at least one newly initiated claim for low/minimal/moderate emetic risk chemotherapy during 2011-2018 were included. We included all approved NK1-RAs: aprepitant, fosaprepitant, rolapitant, and netupitant/palonosetron. A multivariable predictive logistic regression model was used to assess patient demographic and socioeconomic characteristics, as well as health system factors associated with NK1-RA overuse.

RESULTS: Out of 19,112 patients included, 7.8% (n=1,482) of women received a NK1-RA. As compared to women ≥75 years old, those aged 50-64 and 65-74 years were 2.2 and 1.7 times more likely to receive NK1-RAs, respectively. Black women (Adjusted Odds Ratio (aOR):1.324; 95% Confidence Interval (95%CI): 1.109-1.581), women with metastatic stage cancer (aOR: 1.233; 95%CI: 1.038-1.464), those living in the Midwest region (aOR:1.296;95% CI: 1.049-1.601), enrolled in Medicare low income subsidy (aOR: 1.364 ;95%CI: 1.005-1.853), or with a Point of Service insurance type (aOR:1.282; 95%CI: 1.009-1.630), had increased odds of receiving NK1-RA compared to their respective counterparts. Additionally, patients with no comorbidities and those with mental health conditions were 62% and 31% more likely to receive NK1RAs, respectively.

CONCLUSIONS: A little less than 10% of patients with breast cancer initiating low/minimal/moderate emetic risk chemotherapy were prescribed NK1-RAs. Variability in NK1-RAs overuse was driven by certain patient and healthcare related factors. Continued education about these recommendations is important to achieve value-based cancer care.