Cost Utility Analysis of the Cervical Artificial Disc vs Fusion for the Treatment of 2-Level Symptomatic Degenerative Disc Disease: 5-Year Follow-up

Abstract

Background: The cervical total disc replacement (cTDR) was developed to treat cervical degenerative disc disease while preserving motion.

Objective: Cost-effectiveness of this intervention was established by looking at 2-year follow-up, and this update reevaluates our analysis over 5 years.

Methods: Data were derived from a randomized trial of 330 patients. Data from the 12-Item Short Form Health Survey were transformed into utilities by using the SF-6D algorithm. Costs were calculated by extracting diagnosis-related group codes and then applying 2014 Medicare reimbursement rates. A Markov model evaluated quality-adjusted life years (QALYs) for both treatment groups. Univariate and multivariate sensitivity analyses were conducted to test the stability of the model. The model adopted both societal and health system perspectives and applied a 3% annual discount rate.

Results: The cTDR costs $1687 more than anterior cervical discectomy and fusion (ACDF) over 5 years. In contrast, cTDR had $34 377 less productivity loss compared with ACDF. There was a significant difference in the return-to-work rate (81.6% compared with 65.4% for cTDR and ACDF, respectively; P = .029). From a societal perspective, the incremental cost-effective ratio (ICER) for cTDR was -$165 103 per QALY. From a health system perspective, the ICER for cTDR was $8518 per QALY. In the sensitivity analysis, the ICER for cTDR remained below the US willingness-to-pay threshold of $50 000 per QALY in all scenarios (-$225 816 per QALY to $22 071 per QALY).

Conclusion: This study is the first to report the comparative cost-effectiveness of cTDR vs ACDF for 2-level degenerative disc disease at 5 years. The authors conclude that, because of the negative ICER, cTDR is the dominant modality.

Abbreviations: ACDF, anterior cervical discectomy and fusionAWP, average wholesale priceCE, cost-effectivenessCEA, cost-effectiveness analysisCPT, Current Procedural TerminologycTDR, cervical total disc replacementCUA, cost-utility analysisDDD, degenerative disc diseaseDRG, diagnosis-related groupFDA, US Food and Drug AdministrationICER, incremental cost-effectiveness ratioIDE, Investigational Device ExemptionNDI, neck disability indexQALY, quality-adjusted life yearsRCT, randomized controlled trialRTW, return-to-workSF-12, 12-Item Short Form Health SurveyVAS, visual analog scaleWTP, willingness-to-pay.

Figures

FIGURE 1.

Markov model schematic. ACDF, anterior cervical discectomy and fusion; cTDR, cervical total disc replacement.

FIGURE 2.

Probabilistic sensitivity analysis: cost-effectiveness acceptability curve of cervical total disc replacement (cTDR) in comparison with anterior cervical discectomy and fusion (ACDF) from a societal perspective and a health system perspective. The curve shows the probability that cTDR is cost-effective in comparison with ACDF for a range of maximum willingness to pay per quality-adjusted life year (QALY) gained. The probability was derived from 3000 rounds of simulation that randomly sample parameter values from the parameter distributions assigned. Societal perspective includes both direct medical cost and productivity loss. Health system perspective includes only direct medical cost. Color version available online only.

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