Cost-Effectiveness of Early Surgical Intervention for Asymptomatic Cervical Spinal Cord compression: A Markov Model Analysis.
Academic Article
Overview
abstract
BACKGROUND CONTEXT: Asymptomatic cervical spinal cord compression (ACSCC) is common in aging populations and can progress to degenerative cervical myelopathy (DCM). The management of ACSCC remains controversial, with uncertainty about whether early prophylactic surgery provides sufficient benefit to justify its risks and costs. PURPOSE: To evaluate the cost-effectiveness of early anterior cervical discectomy and fusion (ACDF) compared to observation in patients with ACSCC and to identify the progression rate threshold at which early surgery becomes economically favorable. STUDY DESIGN/SETTING: Economic evaluation using a state-transition Markov model from the U.S. healthcare payer perspective, simulating a lifetime horizon. PATIENT SAMPLE: A hypothetical cohort of 10,000 patients with ACSCC, aged to reflect a typical Medicare population, was modeled. Transition probabilities were derived from published natural history and surgical outcome studies. OUTCOME MEASURES: The primary outcomes were quality-adjusted life years (QALYs), derived from validated self-report measures (SF-6D and EQ-5D utilities mapped to modified Japanese Orthopaedic Association (mJOA) severity states). No physiologic measures such as imaging or electrodiagnostics were modeled. Functional outcomes included complication rates, reoperation rates, and lifetime healthcare utilization expressed as costs in 2022 USD. Together, these measures allowed calculation of incremental cost-effectiveness ratios (ICERs) to compare early ACDF against observation with delayed surgery upon progression. METHODS: Seven health states were modeled: asymptomatic, mild, moderate, severe myelopathy, postoperative without complications, postoperative with complications, and death. Transition probabilities, utilities, and costs (Medicare reimbursement, 2022 USD) were obtained from literature. Early ACDF was compared to observation with surgery only upon progression. Probabilistic sensitivity analyses with 10,000 Monte Carlo simulations and one-way sensitivity analyses on progression rates were performed. A 3% annual discount rate was applied. RESULTS: In the base case, observation yielded 15.01 QALYs at a discounted lifetime cost of $8,066 per patient. Early ACDF yielded 15.26 QALYs at $28,106, resulting in an incremental cost of $20,040 and a QALY gain of 0.241 (ICER $83,015/QALY). At a $50,000/QALY threshold, early ACDF was cost-effective in 35.5% of simulations; at $100,000/QALY, in 56.2%. Threshold analysis showed that early surgery became cost-effective only when annual progression risks exceeded ∼3.5% from asymptomatic→mild or ∼11% from mild→moderate myelopathy. Per 10,000 patients, early ACDF resulted in 9,996 surgeries, 2,050 index complications, and 3,040 reoperations, compared with 8,843 surgeries, 1,814 index complications, and 2,049 reoperations under observation. CONCLUSIONS: Early surgery for ACSCC is not cost-effective under current progression estimates but may be justified in high-risk patients with rapid progression. These findings support a risk-stratified approach, emphasizing early intervention only for patients with predictive biomarkers or imaging features of deterioration.
