Evoke Closed Loop Spinal Cord Stimulation System May Be Cost Effective for Treatment of Chronic Back, Leg Pain

An economic analysis using data from the EVOKE randomized clinical trial (NCT02924129) suggests that the Evoke Closed Loop Spinal Cord Stimulation (SCS) System (Saluda Medical, Bloomington, MN) may have cost benefits in the treatment of chronic back and leg pain when compared with open loop SCS therapy. The results of this study were published in The Clinical Journal of Pain.

In this cost-unit analysis, researchers developed an economic model to estimate the costs of the Evoke Closed Loop SCS vs open loop SCS when used for the treatment of chronic back and leg pain from the perspective of the UK National Health Services. Researchers considered a potential patient population consisting of adults aged 18 to 80 years with chronic pain of the back and legs refractory to conventional therapy with and without a history of back surgery. Candidates for SCS had pain scores on the Visual Analog Scale (VAS) of 60+ mm, Oswestry Disability Index (ODI) scores of 41-80, had no prior use of SCS, and were stable on pain medication. Costs used in the model were based on published sources for device costs, healthcare use depending on response to the treatment, as well as surgical removal of devices.

A 2-stage model was developed consisting of a decision tree for stage 1 reflecting the clinical pathway up to 12 months following SCS implantation followed by a Markov model (stage 2) that explored long-term clinical pathways up to 15 years. Results from the base case analysis revealed that the Evoke Closed Loop SCS was more cost saving and generated more quality-adjusted life years (QALY) compared with open loop SCS (7.19 vs 6.23 QALYs, respectively) over 15 years. Results from a scenario analysis indicated that the Evoke Closed Loop SCS was more cost effective compared with open loop SCS after 2 years in patients characterized as ‘high responders’.

“This new analysis reinforces the economic case for utilizing devices which have demonstrated long-term therapy durability,” said Corey Hunter, MD, Assistant Professor, Mt. Sinai Hospital.

Open loop SCS therapy relies on patients or caregivers to monitor and respond to changes in pain whereas closed loop SCS therapy responds automatically to readings from sensor inputs for parameter modulation.