Cost-minimisation analysis of intravenous versus subcutaneous trastuzumab regimen for breast cancer management in Hong Kong.

Abstract

In 2017, breast cancer was the most common cancer and third leading cause of cancer death among women in Hong Kong. Approximately 20% of patients were human epidermal growth factor receptor-2 (HER2)-positive. This study was conducted to investigate cost differences between intravenous and subcutaneous trastuzumab regimens in Hong Kong using medical resources utilisation data from other countries. A cost-minimisation model was developed to compare the cost of total care, including direct medical cost and full-time equivalent (FTE) hours. The drug acquisition cost was obtained from the manufacturer, whereas the costs for hospitalisation and clinic visits were acquired from the Hong Kong Gazette. Time (in FTE hours) was determined by literature review. All costs were expressed in US dollars (US$1 = HK$7.8). Costs were not discounted because of the short time horizon. One-way deterministic sensitivity analysis was performed to identify the effects of changes in drug acquisition cost, changes in FTE hours (based on confidence intervals reported), and changes in body weight (±20%). Literature review indicated that 0.18 FTE hour of nursing time (7.9 hours) and 0.14 FTE hour of pharmacist time (6.2 hours) could be saved each week if the subcutaneous formulation was used. Using data in 2017, after 18 cycles of treatment with subcutaneous trastuzumab, the drug acquisition and healthcare professional time costs were reduced by US$9451.28 and US$566.16, respectively, yielding an annual savings of over US$8 million. The subcutaneous formulation of trastuzumab is a potential cost-saving therapy for HER2-positive breast cancer patients in Hong Kong. The drug acquisition cost was the parameter with the greatest effect on the total cost of treatment.