Is surgery for cervical spondylotic myelopathy cost-effective? A cost-utility analysis based on data from the AOSpine North America prospective CSM study.

OBJECT

Surgical intervention for appropriately selected patients with cervical spondylotic myelopathy (CSM) has demonstrated favorable outcomes. This study evaluates the cost-effectiveness of this type of surgery in terms of cost per quality-adjusted life year (QALY) gained.

METHODS

As part of a larger prospective multicenter study, the direct costs of medical treatment for 70 patients undergoing surgery for CSM at a single institution in Canada were retrospectively obtained from the hospital expenses database and physician reimbursement data. Utilities were estimated on the entire sample of 278 subjects enrolled in the multicenter study using SF-6D-derived utilities from 12- and 24-month SF-36v2 follow-up information. Costs were analyzed from the payer perspective. A 10-year horizon with 3% discounting was applied to health-utilities estimates. Sensitivity analysis was performed by varying utility gain by 20%.

RESULTS

The SF-6D utility gain was 0.0734 (95% CI 0.0557-0.0912, p < 0.01) at 12 months and remained unchanged at 24 months. The 10-year discounted QALY gain was 0.64. Direct costs of medical treatment were estimated at an average of CaD $21,066. The estimated cost-utility ratio was CaD $32,916 per QALY gained. The sensitivity analysis showed a range of CaD $27,326-$40,988 per QALY gained. These estimates are within the limits for medical procedures that have an acceptable cost-utility ratio.

CONCLUSIONS

Surgical treatment for CSM is associated with significant improvement in health utilities as measured by the SF-6D. The direct cost of medical treatment per QALY gained places this form of treatment within the category deemed by payers to be cost-effective.