Prescription of Prophylactic Antiemetic Drugs for Patients Receiving Chemotherapy With Minimal and Low Emetic Risk

IMPORTANCE: The use of antiemetic drugs for patients receiving chemotherapy with low or minimal emetic risk has been recognized as a growing concern for health care costs and patients’ welfare. Relatively few studies have examined antiemetic prophylaxis or treatment of emesis associated with chemotherapy with lower emetic risk. OBJECTIVE: To describe the pattern in Japan of overprescribing prophylactic antiemetic drugs to patients who have received intravenous chemotherapy with minimal or low emetic risk. DESIGN, SETTING, AND PARTICIPANTS: This secondary analysis of a health insurance claims database linked with the hospital-based cancer registry of 122 designated cancer care hospitals covered the period from September 1, 2010, to December 31, 2012. Data were included from patients who (1) were diagnosed with breast, lung, colorectal, stomach, cervical, or prostate cancer; (2) were 20 years or older at the time of the diagnosis; and (3) received intravenous chemotherapy with minimal or low emetic risk. The data from patients with advanced stage cancer (stage IV) were excluded. Data were analyzed from March 20, 2014, to June 30, 2016. MAIN OUTCOMES AND MEASURES: The percentage of chemotherapy administration involving patients prescribed prophylactic antiemetic drugs, namely, a neurokinin 1 receptor antagonist, serotonin receptor antagonist, and/or dexamethasone, was calculated. The costs of potentially unnecessary antiemetic drugs were estimated using the National Health Insurance drug price list for 2011. RESULTS: A total of 8545 patients (5886 women [68.9%] and 2659 men [31.1%]; mean [SD] age, 61.9 [12.8] years) undergoing 73 577 administrations of chemotherapy with minimal emetic risk (2464 patients; 22 619 administrations) or low emetic risk (6081 patients; 50 958 administrations) were identified. Of these, patients who received 24 373 administrations of chemotherapy with a low emetic risk (47.8%) and 633 administrations of chemotherapy with a minimal emetic risk (2.8%) were prescribed serotonin receptor antagonists and dexamethasone. Outpatients in the low emetic risk group underwent more frequent administration of chemotherapy that included prescription of both drugs (53.1% of the chemotherapy; 95% CI, 51.6%-54.7%) compared with inpatients (33.7% of the chemotherapy; 95% CI, 31.7%-35.9%). Consequently, approximately ¥170 million (US $1.6 million) was unnecessarily spent on prophylactic antiemetic drugs for these patients. CONCLUSIONS AND RELEVANCE: A substantial number of patients receiving chemotherapy with minimal and low emetic risk were prescribed potentially unnecessary prophylactic antiemetic drugs. The judicious use of these drugs could spare the burden of extra costs and the potential risk for adverse effects for patients.