変形性膝関節症の保存的薬物療法に対する防已黄耆湯の薬剤経済分析

Abstract

We conducted a pharmacoeconomic analysis on the treatment of knee osteoarthritis (K-OA) in which we compared the use of Boiogito and oral NSAIDs. The outcome criterion used for the analysis was the numbers (and %) of patients achieving the endpoint for K-OA treatment. The probability of effectiveness was predicted by calculating the number of patients achieving the endpoint or treatment goal for each treatment group, (TJ-20 (Boiogito, Tsumura) group, TJ 20 plus NSAIDs group and NSAIDs group). We conducted the analysis from the point of view of the payer. The cost of each treatment regimen was calculated for an eight-week period using cost effectiveness models based on medical service fee scores (revised in April, 2004). By calculating costs in this way, we obtained the numbers of patients achieving the treatment goals and probability of effectiveness in the three treatment groups. The probability of effectiveness for the TJ-20, TJ 20 plus NSAIDs, and NSAIDs groups were 17 of 31 patients (54.8%), 21 of 33 patients (63.6%) and 10 of 20 patients (50.0%) respectively, showing that the highest probability of effectiveness was in the TJ 20 plus NSAIDs group. The results of the cost effectiveness analysis showed that the treatment costs necessary for one patient to achieve the treatment goal for K-OA with TJ-20, TJ 20 plus NSAIDs, and NSAIDs were ¥22,002, ¥29,248 and ¥23,610, respectively. Treatment using TJ-20 alone was thus the most inexpensive.