Cost effectiveness of implanting a prosthesis after anterior cervical discectomy for radiculopathy: results of the NECK randomized controlled trial

Abstract

BACKGROUND CONTEXTIn the treatment of cervical radiculopathy due to a herniated disc, potential surgical treatments include: anterior cervical discectomy (ACD), ACD and fusion using a cage (ACDF), and anterior cervical disc arthroplasty (ACDA). Previous publications yielded comparable clinical and radiological outcome data for the various implants, but research on their comparative costutility has been inconclusive. PURPOSETo evaluate the cost utility of ACD, ACDF, and ACDA. STUDY DESIGNCost-utility analysis. PATIENT SAMPLEAbout 109 patients with cervical radiculopathy randomized to undergo ACD, ACDF, or ACDA as part of the NEtherlands Cervical Kinetics trial. OUTCOME MEASURESQuality-adjusted life-years (QALYs) estimated from patient-reported utilities using the EuroQol-5D questionnaire and EuroQol Visual Analogue Scale (EQ VAS), measured at baseline, 2, 4, 8, 12, 26, 52, and 104 weeks postprocedure. Societal costs including admissions to hospital (related and otherwise), GP visits, specialist visits, physical therapy, medications, home care, aids, informal care, productivity losses, and out of pocket condition-related expenses. METHODSThe cost utility of the competing strategies over 1 and 2 years was assessed following a net benefit (NB) approach, whereby the intervention with the highest NB among competing strategies is preferred. Cost effectiveness acceptability curves were produced to reflect the probability of each strategy being the most cost effective across various willingness-to-pay (WTP) thresholds. Five sensitivity analyses were conducted to assess the robustness of results. RESULTSACDF was more likely to be the most cost-effective strategy at WTP thresholds of €20,000 to 50,000/QALY in all but one of the analyses. The mean QALYs during the first year were 0.750, 0.817, and 0.807 for ACD, ACDF, and ACDA, respectively, with no significant differences between groups. Total healthcare costs over the first year were significantly higher for ACDA, largely due to the higher surgery and implant costs. The total societal costs of the three strategies were €12,173 for ACD, €11,195 for ACDF, and €13,746 for ACDA, with no significant differences between groups. CONCLUSIONOur findings demonstrate that ACDF is likely to be more cost-effective than ACDA or ACD at most WTP thresholds, and this conclusion is robust to most sensitivity analyses conducted. It is demonstrated that the difference in costs is mainly caused by the initial surgical costs and that there are only minimal differences in other costs during follow-up. Since clinical data are comparable between the groups, it is to the judgment of the patient and surgeon which intervention is applied.