RESULTS
NRS, Pain, radiculopathy, pain, implant-related wound infections, TG, NTG
ADVERSE EVENTS, RADICULOPATHY, ADVERSE EVENT
From June 2017 to September 2018, 137 patients were assessed for eligibility, with 105 patients proceeding to enrolment. Of the 105 participants, 54 were randomized to the screening TG. Seven of the patients in TG withdrew before the screening trial; of the remaining 47, an unsuccessful screening trial was observed for 5 (11%) patients and 42 (89%) patients had a successful screening trial and were implanted with an SCS system. Forty-nine of the 51 NTG patients received an SCS implant. Thirty TG patients and 36 NTG patients completed the follow-up at 36 months (Figure). Loss to follow-up in all instances was due to failure to reach the patients via telephone (maximum of 3 attempts), email, and letter.Trial profile. AEs, adverse event; NTG, no trial group; SAE, serious adverse event; TG, trial group.The only difference between the TG and NTG groups' baseline characteristics and outcome ratings was the duration of pain, which was slightly longer in the NTG group. Participants in the study had a mean NRS pain score of 7.5, an average age of 50.4 years, and fairly equal sex representation. The most frequent primary diagnoses in both groups were PSPS-T2 (52% TG, 55% NTG) and radiculopathy (15% TG, 23% NTG).At 36-month follow-up, there was no difference in the primary outcome of clinic-assessed NRS score between TG and NTG (adjusted mean difference: −0.60, 95% CI: −1.83 to 0.63; see Table Complete Case Analysis of Primary and Secondary Continuous OutcomesEQ-5D, EuroQol-5 Dimension; EQ-VAS, EuroQol Visual Analog Scale; NRS, numerical rating scale; NTG, no trial group; TG, trial group.Means, standard deviation, and unadjusted and adjusted mean difference between groups calculated based on available data (complete case analysis). No imputation of missing data was performed.Adjusted for baseline value of the measure (36-month follow-up data only), sex, age (≥65 vs < 65 years), presence of PSPS‐T2 (yes or no), and site.Improvements were seen in EQ-5D-5L and EuroQol Visual Analog Scale (EQ-VAS) from baseline to 36 months in both groups. There was no evidence of difference between TG and NTG groups for EQ-5D utility scores (adjusted mean difference: −0.02, 95% CI: −0.13 to 0.10). The mean change from baseline at 36-month follow-up for EQ-5D utility scores observed was around 0.2 for both TG and NTG groups. Considering a MCID of 0.074 for the EQ-5D utility scores,The proportion of patients who were responders considering a ≥50% (33% TG; 31% NTG) or ≥30% (53% TG; 42% NTG) reduction in pain from baseline were not statistically different between the TG and NTG groups (Table Responders Per Group According to Level of Pain Reduction (Complete Case Analysis at 36-Month Follow-up)NRS, numerical rating scale; NTG, no trial group; TG, trial group.Risk ratio between groups calculated based on available data (complete case analysis). No imputation of missing data was performed.Adjusted for baseline value of NRS, sex, age (≥65 vs < 65 years), presence PSPS-T2 of (yes or no), and site.Considering a MCID of 2 in the NRS,Pain Intensity Per Group According to SCS Waveform (Complete Case Analysis at 36-Month Follow-up)HF, high-frequency; NRS, numerical rating scale; NTG, no trial group; SCS, spinal cord stimulation; TG, trial group.Programming method missing for 1 patient in the TG group.Since the primary 6-month end point, there were 2 explants of the SCS device. One explant in TG because the device was not switching on; a new IPG has been scheduled for implant. There was one explant in NTG because of pain at the IPG site. Between six- and 36-month follow-ups, there were 3 adverse events (AEs) corresponding to fractured leads for 2 patients (1 TG and 1 NTG) and 1 patient in TG reporting problems charging the device; none of these AEs resulted in device explant. Overall (ie, during the 36-month study period, which included 2 additional device explants in TG because of implant-related wound infections), the likelihood of having an explant was not significantly different between TG (3 explants from a total of 54 patients) and NTG groups (1 explant from a total of 51 patients; unadjusted odds ratio 0.34, 95% CI 0.03-3.4). Similarly, no difference was observed for the likelihood of reporting an AE (TG [14 out of 54 patients]; NTG [12 out of 51 patients]; odds ratio 0.88, 95% CI 0.36-2.14).