Cost-utility Analysis of Evoke closed-loop Spinal Cord Stimulation for Chronic Back and Leg Pain.

OBJECTIVES: The effectiveness of Evoke closed-loop spinal cord stimulation (CL-SCS), a novel modality of neurostimulation, has been demonstrated in a randomised controlled trial (RCT). The objective of this cost-utility analysis was to develop a de novo economic model to estimate the cost-effectiveness Evoke CL-SCS when compared to open-loop SCS (OL-SCS) for the management of chronic back and leg pain.

METHODS: A decision tree followed by a Markov model were used to estimate costs and outcomes of Evoke CL-SCS versus OL-SCS over a 15-year time horizon from the UK National Health Service perspective. A 'high-responder' health state was included to reflect improved levels of SCS pain reduction recently reported. Results are expressed as incremental cost per quality adjusted life year (QALY). Deterministic and probabilistic sensitivity analysis (PSA) were conducted to assess uncertainty in the model inputs.

RESULTS: Evoke CL-SCS was estimated to be the dominant treatment strategy at approximately 5 years post-implant (i.e., generates more QALYs while cost-saving compared to OL-SCS). PSA showed that Evoke CL-SCS has a 92% likelihood of being cost-effective at a willingness to pay threshold of £20,000/QALY. Results were robust across a wide range of scenario and sensitivity analyses.

DISCUSSION: The results indicate a strong economic case for the use of Evoke CL-SCS in the management of chronic back and leg pain with or without prior spinal surgery with dominance observed at approximately 5 years.