Effectiveness of Using a Drug Cost Calculator to Improve Patients’ Understanding of Drug Costs in Advanced Breast Cancer: A Multicenter, Randomized Controlled Trial

Purpose : Cost discussions are essential but seldom conducted in routine oncology care. Here, we evaluated whether using a drug cost calculation tool improves patients’ understanding of drug costs and their perception of the importance of drug costs in making treatment decisions for advanced breast cancer (ABC). Methods : This multicenter, open-label, randomized phase 2 trial was conducted at four hospitals in Japan. Eligible patients with ABC were randomized on a one-to-one basis to the drug cost calculator or usual-explanation group. Physicians in the calculator group used the calculator to explain out-of-pocket drug costs during treatment consultations. The co-primary endpoints were patients’ scores on two five-point Likert-scale questions assessing (1) understanding of drug costs and (2) perception of their importance in treatment decisions. Results : Ninety-eight patients were enrolled, of whom 69 were randomized between September 2019 and November 2023. The median score for “understanding of drug costs” was 4 (IQR, 3–4) and 3 (IQR, 2–4) points in the calculator and usual-explanation groups, respectively ( P = 0.04). For “importance of drug costs,” the median scores were 4 (IQR, 4–5) and 4 (IQR, 3–4) points in the calculator and usual-explanation groups, respectively. The scores for “discussion of financial burden” tended to be higher in the calculator group. Consultation times were comparable between the groups. Conclusion : Using the drug cost calculator tended to improve patients’ understanding of drug costs and facilitated cost communication without prolonging consultation time. Trial registration : University Hospital Medical Information Network Clinical Trials Registry (No. UMIN000039904; March 23, 2020).