Two-year cost-effectiveness analysis of alternate-level instrumentation in open-door cervical laminoplasty: secondary analysis of a randomized controlled trial.

In 30 seconds

This secondary cost-effectiveness analysis of a prospective, multicentre randomised controlled trial compared alternate-level (skip) with every-level instrumentation during C3-C6 open-door laminoplasty in patients aged ≥60 years with degenerative cervical myelopathy. Among 129 patients with complete 2-year data, QALYs did not differ significantly (ΔQALY = 0.035; 95% CI, -0.083 to 0.152), while mean direct medical costs were lower with skip-fixation (ΔCost = USD -1,460; 95% CI, -2,834 to -173). At a willingness-to-pay threshold of USD 45,900 per QALY, the estimated probability that skip-fixation was cost-effective was 86.3%.

Key findings

• Two-year QALYs showed no statistically significant difference between groups (ΔQALY = 0.035; 95% CI, -0.083 to 0.152).
• Mean 2-year direct medical costs were lower with skip-fixation (ΔCost = USD -1,460; 95% CI, -2,834 to -173).
• At a willingness-to-pay threshold of USD 45,900 per QALY, skip-fixation had an 86.3% probability of being cost-effective.
• Scenario analyses found a greater economic advantage for skip-fixation when higher-cost plate fixation was assumed.

Why it matters

The analysis adds an economic comparison to trial evidence that skip-fixation provides noninferior JOA-score improvement. Lower observed costs without a significant QALY difference suggest that using fewer instrumented levels may offer value within the Japanese public insurance system. The findings also indicate that the economic case may depend on implant costs, so cost-effectiveness may not transfer unchanged across settings.

What to keep in mind

The analysis included 129 patients with complete 2-year cost and utility data and reflects costs under the Japanese public health insurance system; its economic findings may not generalise to other settings.