The purpose of this study was to propose a time-series modeling and simulation (M&S) strategy for probabilistic cost-effective analysis in cancer chemotherapy using a Monte-Carlo method based on data available from the literature. The simulation included the cost for chemotherapy, for pharmaceutical care for adverse events (AEs) and other medical costs. As an application example, we describe the analysis for the comparison of four regimens, cisplatin plus irinotecan, carboplatin plus paclitaxel, cisplatin plus gemcitabine (GP), and cisplatin plus vinorelbine, for advanced non-small cell lung cancer. The factors, drug efficacy explained by overall survival or time to treatment failure, frequency and severity of AEs, utility value of AEs to determine QOL, the drugs' and other medical costs in Japan, were included in the model. The simulation was performed and quality adjusted life years (QALY) and incremental cost-effectiveness ratios (ICER) were calculated. An index, percentage of superiority (%SUP) which is the rate of the increased cost vs. QALYgained plots within the area of positive QALY-gained and also below some threshold values of the ICER, was calculated as functions of threshold values of the ICER. An M&S process was developed, and for the simulation example, the GP regimen was the most cost-effective, in case of threshold values of the ICER $70000/ year, the %SUP for the GP are more than 50%. We developed an M&S process for probabilistic cost-effective analysis, this method would be useful for decision-making in choosing a cancer chemotherapy regimen in terms of pharmacoeconomic.Key words pharmacoeconomic; cost-effectiveness; cancer chemotherapy; Monte Carlo simulation; modeling and simulation; non-small cell lung cancer In cancer chemotherapy, an important concern for patients is the efficacy of treatment, usually expressed by indices such as survival time and performance status. The high cost of cancer chemotherapy is a burden for both patients and the national economy; for example, the total cost of cancer therapy in the United States reported by National Cancer Institute (NCI) was $157 billion in 2010.1) It has also been reported that these costs may increase at a faster rate than overall medical expenditure 2) because new targeted anticancer therapies such as monoclonal antibodies and small-molecule inhibitors will be adopted as standard therapies, and therefore, more efficient but more expensive therapies will be used.A concept of pharmacoeconomics has been applied to a clinical pharmacy practice, 3,4) and a health care evaluation.
5)Several types of cost-effective analyses have been performed for choosing the optimal chemotherapy regimens for cancer patients. [6][7][8] The objectives of these cost-effective analyses were to compare two or more regimens from the viewpoint of increasing cost per increasing efficacy. From a pharmaceutical viewpoint, in order to choose the optimal regimen that provides the best cost-effective ratio, information regarding both treatments' efficacy and the frequency an...