Higher trial-to-implant ratio found at high-volume SCS centres


A study carried out by Kelly Ryan Murphy (Duke University Medical Center, Durham, USA) and colleagues has found that centres with high-volume spinal cord stimulation implanters have a higher trial-to-implant rate than centres with less experienced implanters.

The study authors sought to investigate this volume-outcome effect due to its implications for healthcare resource utilisation and pain management. They hypothesised that there is a volume-outcome effect where chronic pain patients who are treated by high-volume spinal cord stimulation implanters will have higher trial-to-permanent implant conversion rates.

To carry out the study, published in the journal Neuromodulation, Murphy et al designed a large, retrospective analysis using the Truven MarketScan database analysing adult spinal cord stimulation patients with provider information available, with or without implantable pulse generator (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.

“A total of 17,850 unique trial implants were performed by 3028 providers. Of 13,879 patients with baseline data available, 8981 (64.7%) progressed to permanent spinal cord stimulation. 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±13.4 years vs. 53±13.4 years, p=0.0026), Medicare/Medicaid (47.8% vs. 35% low volume, p<0.0001), Southern region (53.5% vs. 38.9% low volume, p<0.0001), and higher Charlson comorbidity scores (1 [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),” the authors report.

The study clearly shows that in this US-wide analysis high volume providers achieved higher trial-to-permanent implant spinal cord stimulation 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 healthcare resource utilisation differences,” Murphy et al add.