Cost-effectiveness of lumbar fenestration surgery in the Japanese universal health insurance system.

Abstract

Healthcare costs are a global concern, and cost-effectiveness analyses of interventions have become important. However, data regarding cost-effectiveness are limited to a few medical fields. The purpose of our study was to examine the Japanese universal health insurance system cost per quality-adjusted life year (QALY) for lumbar fenestration surgery. Forty-eight patients who underwent fenestration for lumbar degenerative spinal canal stenosis between July 2013 and September 2015 were included. Effectiveness was evaluated by measuring the EuroQOL 5-dimension (EQ-5D), Short-Form 8 physical component summary (PCS), and visual analog scale (VAS). Cost was analyzed from the perspective of the public healthcare payer. Effectiveness and cost were measured 1 year after surgery. QALYs were calculated by multiplying the utility value (EQ-5D) and life years. Only direct costs based on actual reimbursements were included. Cost per QALY with a 5-year time horizon with a 2% discount rate was estimated. Sensitivity analysis was performed by varying the time horizon (2 years or 10 years). Mean total cost 1 year after fenestration surgery was 1,254,300 yen (standard deviation [SD], 430,000 yen; median, 1,172,300 yen). Operative cost was 406,800 yen (SD, 251,500 yen; median, 363,000 yen). Mean gained score was 0.21 for EQ-5D (SD, 0.18; median, 0.24), 11 for PCS (SD, 10; median, 12), and -43 for VAS (SD, 34; median, -38). Cost per QALY was 1,268,600 yen. Sensitivity analysis demonstrated that cost per QALY with a 10-year time horizon was 679,300 yen and that with a 2-year time horizon was 3,004,600 yen. Cost per QALY of lumbar fenestration with a 5-year time horizon was 1,268,600 yen (11,532 US dollar), which was below the widely accepted benchmark (cost per QALY <5,000,000-6,500,000 yen (50,000 US dollars)). Fenestration is a cost-effective intervention.