Two-level CTDR was more cost-effective compared to ACDF at 5-year follow-up

SAN DIEGO — Two-level cervical total disc replacement proved to be more cost-effective than anterior cervical discectomy and fusion at 5-year follow-up for patients with degenerative disc disease, according to a cost -utility analysis.

Jared D. Ament, MD, MPH, presented these findings at the Cervical Spine Research Society Annual Meeting.

“We found that at 5 years, two-level artificial disc replacement was cost-effective compared to two-level anterior cervical discectomy [ACDF] and fusion and in many cases, was actually the dominant strategy. Return to work data suggested a more expedient recovery, and this economic model was robust enough to stand up to a rigorous sensitivity analysis,” Ament said.

Cost-utility analysis

Ament and colleagues conducted the cost-utility analysis using data from a randomized controlled trial conducted by LDR Medical that followed 330 patients during 5 years. They used linear regression to construct health states by stratifying Neck Disability Index (NDI) and VAS scores.

The investigators calculated costs by extracting diagnosis-related group (DRG) codes from billing data and then they applied 2014 Medicare reimbursement rates.

The data showed CTDR had an initial higher cost at the time of surgery of $20,488 compared with $16,945 for ACDF. However, when the amounts were adjusted for costs related to adverse events, the cost of CTDR was $1,685 more than ACDF over 5 years.

Less productivity loss

Ament noted CTDR resulted in less lost productivity at $55,447 vs. $91,824 for patients who underwent ACDF.

“We looked at return to work and, not surprisingly, people with less disability [in the study] were more likely to return to work. [In] the follow-up, the patients returned quicker in the artificial disc group than the ACDF group,” he said.

Among patients who underwent CTDR, 81.6% were able to return to work compared with 65.4% after ACDF.

More QALYs with CTDR

A Markov model built by Ament and colleagues to evaluate quality-adjusted life years (QALYs) in both patient cohorts showed 3.574 QALYs for patients with CTDR and 3.376 QALYs for patients with ACDF 5 years after treatment.

At 5-year follow-up, the incremental cost effectiveness ratio (ICER) from a societal perspective for the CTDR cohort was -$165,103 per QALY. From a health system perspective, the ICER for CTDR was $8,518 per QALY, according to the study results.

“In both scenarios, two-level artificial disc replacement was cost-effective compared with ACDF. What was interesting, when we factored in the difference in productivity loss, from the societal perspective, CTDR was the dominant surgical strategy, meaning, you got more for less money,” Ament said.

After assessing thresholds, Ament and colleagues noted that ACDF only became cost-effective in their model when CTDR cost 44% to 250% more than the current DRG reimbursements.

Ament and colleagues concluded that due to the negative ICER for CTDR, it is therefore the dominant modality for patients who have two-level degenerative disc disease. – by Robert Linnehan

Reference:
Ament JD, et al. Presentation #11. Presented at: Cervical Spine Research Society Annual Meeting; Dec. 3-5, 2015; San Diego.

For more information:

Jared D. Ament, MD, MPH, can be reached at University of California, Davis, Department of Neurological Surgery, 4860 Y. St., Suite 3740, Sacramento, CA 95817; email: jdament@ucdavis.edu.

Disclosure: Ament reports he is a consultant to LDR Medical, which provided funding for the data analysis and preparation of the manuscript.