The Volume-Outcome Effect: Impact on Trial-to-Permanent Conversion Rates in Spinal Cord Stimulation

Abstract

Objectives Conversion rates from trial leads to permanent spinal cord stimulation (SCS) systems have important implications for healthcare resource utilization (HCRU) and pain management. We hypothesized conversion rates differ based on provider implant volume. Materials and Methods We designed a large, retrospective analysis using the Truven MarketScan database analyzing adult SCS patients with provider information available, with or without IPG implantation from the years 2007 to 2012. Patients were divided into three provider-based groups: high (>25), medium (9–24), and low (3–8) volume providers. Univariate and multivariate models identified factors associated with successful conversion. Results A total of 17,850 unique trial implants were performed by 3,028 providers. Of 13,879 patients with baseline data available, 8,981 (64.7%) progressed to permanent SCS. Higher volume providers were associated with slightly higher conversion rates (65.9% vs. 63.3% low volume, p=0.029), explant rates (9.2% vs. 7.7% medium volume, p=0.026), younger age (52.0 ± 13.4 years vs. 53.0 ± 13.4 years, p=0.0026), Medicare/Medicaid (47.8% vs. 35.0% low volume, p<0.0001), Southern region (53.5% vs. 38.9% low volume, p<0.0001), and higher Charlson comorbidity scores (1.0 (SD=1.4), p=0.0002). Multivariate regression results showed female gender (1.13 [95% CI: 1.05–1.22], p<0.001) and high volume providers associated with higher odds of successful trial conversion (1.12 [95% CI: 1.02–1.22], p=0.014). Conclusions In this nationwide analysis, high volume providers achieved higher trial-to-permanent SCS conversion rates than lower volume providers. The study has implications for both training requirements and referral patterns to delineate minimum implant experience necessary for provider proficiency. Future studies may be useful to understand HCRU differences.

Effective Relief of Pain and Associated Symptoms With Closed-Loop Spinal Cord Stimulation System: Preliminary Results of the Avalon Study

“…The study enrolled a cohort of subjects with demographics consistent with the larger population undergoing neuromodulation . Conversion rate from trial to permanent system was also consistent with recent studies of modern SCS waveforms .…”

Therapy Habituation at 12 Months: Spinal Cord Stimulation Versus Dorsal Root Ganglion Stimulation for Complex Regional Pain Syndrome Type I and II

“…A similar trend was observed with male subjects in the SCS group demonstrating significantly reduced pain relief at 9-and 12-months, whereas female subjects showed stable pain relief. While differences in pain perception and treatment effects have been noted between males and females, 17,19 it is unknown why male subjects appeared to be more susceptible to habituation of SCS therapy, and a more general analysis of gender differences would be worthwhile.…”

Down the Rabbit Hole: Specialty Influence on SCS Outcomes

“…We acknowledge the significant technical challenges in examining challenging topics such as specialty variation using a large database analyses. In order to control for the potential bias that may be introduced by the observational nature of the study and the Address correspondence to: Shivanand P. Lad (2). We agree that this could be added to the present manuscript in the multivariate analysis and have done so (Table 1).…”