Cost-utility analysis of surgical revascularization versus conservative management for adult moyamoya disease patients with posterior hemorrhage in Japan

This study evaluates the cost-effectiveness of surgical revascularization versus conservative management for adult moyamoya disease (MMD) patients with posterior hemorrhage from the perspective of the Japanese public healthcare payer. We developed a combined decision tree and Markov model for adult posterior hemorrhagic MMD patients (mean age: 41 years; baseline modified Rankin Scale [mRS] 0–2) over a 60-year lifetime horizon with 1-year cycles. We estimated the treatment effect using the composite endpoint hazard ratio (0.07) from the JAM Trial posterior hemorrhage subgroup as a proxy for the effect on recurrent hemorrhage. We informed health utilities with recent EQ-5D-5L data from the Fukuoka Stroke Registry, weighted by the Japan Stroke Data Bank. We estimated direct medical costs based on the national fee schedule. We discounted costs and outcomes at 2% annually. We set the willingness-to-pay threshold at JPY 7,500,000 per quality-adjusted life year (QALY). In the base case, surgical revascularization yielded 21.49 QALYs for JPY 6,323,426 (USD 40,302), compared with 15.59 QALYs and JPY 5,308,637 (USD 33,835) for conservative management. The incremental cost-effectiveness ratio was JPY 172,220 (USD 1,098) per QALY, which falls below the reference value of JPY 7,500,000 per QALY. In scenario analyses with 5- and 10-year horizons, the ICERs were JPY 8,926,784 and JPY 2,031,693 per QALY, respectively. Probabilistic sensitivity analysis also favored surgical revascularization across the modeled parameter distributions. The base-case estimate of surgical efficacy was based on a composite outcome from a small subgroup, and long-term recurrence risks beyond the 5-year trial period remain uncertain. Surgical revascularization is likely to be cost-effective for adult MMD patients with posterior hemorrhage within the Japanese healthcare system, although limited evidence leaves uncertainty about long-term rebleeding risks and the durability of surgical benefit.