Cost-effectiveness of single-level anterior cervical discectomy and fusion for cervical spondylosis.

STUDY DESIGN Cost-effectiveness analysis with retrospective cost analysis and literature review. OBJECTIVE To determine the relative cost-effectiveness of anterior cervical discectomy and fusion (ACDF) with autograft, allograft, and allograft with plating for single-level anterior cervical spondylosis. SUMMARY OF BACKGROUND DATA There are several accepted methods of surgically treating single-level cervical spondylosis anteriorly. No study has clearly demonstrated the superiority of one method over the alternatives. The techniques may differ in their operative risks and resource use, perioperative complications, short-term outcome, and long-term outcome and complications. Formal cost-effectiveness analysis (CEA) provides a structure for analyzing many variables and comparing different treatment outcomes. Sensitivity analysis is used to test the robustness of the model and to determine variables that have significant effects on the results. Future areas of research and refinements of the CEA model can be developed from these findings. METHODS A retrospective review of hospital charges was performed for 78 patients who underwent single-level ACDF with allograft alone or ACDF with allograft and plating (ACDFP). The charges were converted to estimated costs for fiscal year 2000 using the ratio of costs to charges method. A CEA model was developed consisting of a decision-analysis model for the first year postsurgery and a Markov model for the next 4 years after surgery. Probabilities and outcome utilities were estimated from the literature. Outcome was measured in quality-adjusted life years (QALYs), and incremental CEA was performed. Several variables were tested in one-way sensitivity analysis. RESULTS Compared with ACDF with autograft, ACDF with allograft offered an improvement in quality of life at a cost of 496 dollars per QALY. ACDFP provided additional gains in quality of life compared with ACDF with allograft at a cost of 32,560 dollars per QALY in the base case analysis. In sensitivity analysis, these estimates varied between 417 dollars and 741 dollars per QALY and between 19,090 dollars per QALY and domination of ACDFP by ACDF with allograft, respectively. The results were most sensitive to assumptions regarding differences in the length of the postoperative recovery period. CONCLUSIONS ACDF with allograft offers a benefit relative to ACDF with autograft at a cost of 496 dollars per QALY. ACDFP has a benefit relative to ACDF with allograft at an approximate cost of 32,560 dollars per QALY. CEA provides a method for comparing the benefits and risks of these three procedures. Further research needs to be performed regarding these procedures, particularly examining the postoperative recovery period.