Changes in Antiemetic Overuse in Response to Choosing Wisely Recommendations.

Importance: Antiemetics are used to prevent chemotherapy-induced nausea and vomiting in patients with cancer. Newer antiemetic agents (serotonin and neurokinin-1 receptor antagonists) have increased efficacy but are expensive. The American Society of Clinical Oncology's first guideline in the 2013 Choosing Wisely (CW) campaign discouraged overuse of expensive antiemetics in patients with low risk of chemotherapy-induced nausea and vomiting. However, little is known about patterns or trends in antiemetic overuse or whether any change has occurred with the publication of the CW recommendations.

Objective: To estimate the baseline prevalence, trends, determinants, and costs of antiemetic overuse from January 1, 2008, through March 31, 2015.

Design, Setting, and Participants: From January 1, 2008, through March 31, 2015, this observational study applied descriptive (univariate and bivariate) and multivariable logistic regression analyses to longitudinal health insurance enrollment and nationwide MarketScan insurance claims data for 678 220 privately insured patients receiving chemotherapy before and after the October 29, 2013, announcement of the CW guidelines. The baseline prevalence, trends, determinants, and costs of antiemetic overuse were estimated in cases stratified by risk for chemotherapy-induced nausea and vomiting.

Main Outcomes and Measures: Antiemetic use, overuse measure, and expenses before and after the publication of the CW recommendation, with adjustment for patient and health care professional characteristics.

Results: The sample included 678 220 adults who started chemotherapy during the observation period. The average age of the sample was 59.5 years, with 58.2% (n = 394 724) female. Antiemetic overuse occurred in 24.1% (n = 163 451) of patients, with highest rates among those receiving intravenous chemotherapy with high chemotherapy-induced nausea and vomiting risk (32.4% [n = 106 795]). Compared with baseline before the CW, patients had 7.0% lower odds of antiemetic overuse (95% CI, 4.4%-9.5%) during the 6 months after the CW, but this decrease was transitory: the odds of antiemetic overuse were 7.4% (95% CI, 4.6%-10.2%) higher than baseline at 6 months after the CW. Low-risk intravenous chemotherapy agents had overuse that continued to decrease 6 months after the CW. Antiemetic overuse was associated with higher costs. Reducing antiemetic overuse could have paid for 6.1% (95% CI, 5.8%-6.4%) of the chemotherapy drug costs.

Conclusions and Relevance: Antiemetic overuse is prevalent and results in unnecessary spending associated with systemic chemotherapy treatment. Short-term decreases in antiemetic overuse were associated with the CW recommendation, but sustained decreases occurred in only one risk group.