Systematic review and meta-analysis of conventional medical management in a patient population with refractory chronic pain suitable to receive a spinal cord stimulation system

AIM: The aim of this review was to systematically identify all evidence that used conventional medical management (CMM) as a comparator in randomised controlled trials (RCTs) of spinal cord stimulation (SCS) therapy, and to conduct a meta-analysis to investigate if continued CMM provides statistical or clinically meaningful pain relief and whether CMM effects have improved over the last few decades. METHODS: Databases were searched from inception to June 2024 for RCTs that compared SCS to CMM. The primary outcome of the review was absolute change in pain intensity from baseline to the last available follow-up in the CMM group, measured using a visual analogue scale or numerical rating scale. The measure of treatment effect for absolute change and percentage change in pain intensity from baseline was mean difference (MD) and 95% confidence interval (CI). Risk of bias (RoB) was assessed by using the revised Cochrane RoB tool. The protocol for this review is registered on PROSPERO (CRD42023449215). RESULTS: Meta-analysis of absolute change in pain intensity from baseline to last follow-up shows that CMM is not associated with any significant reductions in pain intensity (MD -0.11; 95% CI: -0.32 to 0.11; moderate certainty). Similar results were observed for percent change in pain intensity from baseline to last follow-up (MD -3.22%; 95% CI: -12.59% to 6.14%; moderate certainty). No significant differences were observed when considering decade of publication of the RCT for absolute (p = 0.065; moderate certainty) or percent change in pain intensity (p = 0.524; moderate certainty). Meta-analysis for 6-month follow-up and sensitivity analysis shows similar numerical results. CONCLUSION: Our findings show that continued CMM for a population eligible for SCS does not provide meaningful pain relief and has not considerably changed over the last few decades. The use of CMM as the control to evaluate relative SCS treatment effects should be reassessed.