Cost-Effectiveness Analysis of the Treatment Strategies with or without Opioid Medications in Surgery-Eligible Patients with Osteoarthritis in Japan

Aim: The aim of this study was to evaluate the cost effectiveness of treatment strategies without opioid medications (non-opioid treatment strategy) versus strategies with opioid medications (opioid treatment strategy) among surgery-eligible patients with osteoarthritis (OA) of the knee or hip in Japan. Materials and Methods: We built a Markov cohort model to evaluate outcomes for the treatment strategies in surgery-eligible patients aged ≥ 65 years with OA of the knee or hip in Japan. The opioid treatment strategy as an intervention includes a health state with opioid medication in the treatment pathway. On the other hand, for the non-opioid treatment strategy, there is no health state with opioid medication. A targeted literature review and database analysis were conducted to identify and define the values of the variables included in the model. The time horizon was set to 30 years, and a 2% discount was applied for cost and quality-adjusted life-years (QALYs). Sensitivity analysis and scenario analysis were performed in the model. The outcomes were QALYs and the incremental cost-effectiveness ratio (ICER). Results: In the base-case analysis, the non-opioid treatment strategy was dominant over the opioid treatment strategy and associated with an incremental cost and QALYs of − 53,878 JPY (− 499 USD) and 0.03 QALYs, respectively, in patients with knee OA, and − 54,129 JPY (− 502 USD) and 0.02 QALYs, respectively, in patients with hip OA. One-way sensitivity analysis showed the ICER was most sensitive to the QALY for opioid monotherapy. Probabilistic sensitivity analyses showed a high degree of uncertainty associated with the results. Limitations: Study limitations included assumptions related to transition probabilities of the health states, and a lack of Japanese-specific data for transition probabilities, incidence of adverse events and utility values. Conclusions: This study suggests that the non-opioid treatment strategy is cost effective compared with the opioid treatment strategy in the management of surgery-eligible patients with OA of the knee or hip. However, this final conclusion may not be accurate as the methodology is heavily reliant on assumptions.