ABSTRACT
Given the differing mechanisms thought to underlie therapeutic sub- and supra-perception-based neurostimulative modalities, Spinal Cord Stimulation (SCS) systems designed for combined delivery of these approaches may help improve analgesic outcomes and quality of life, and reduce treatment failures. This multicenter, observational case-series evaluated 188 patients with chronic back and/or leg pain implanted with an SCS device capable of sequential or simultaneous delivery of sub-perception and supra-perception stimulation programming (i.e., combination therapy) at 16 in Europe. Following implantation, patients were provided with an array of advanced supra-perception programs (e.g., paresthesia-based SCS using multiple independent current sources), and a custom set of sub-perception programs optimized with specific waveforms and/or field shapes. A mean overall pain score of 7.9 ± 1.7 (Standard Deviation (SD)) was reported pre-trial (Baseline). Overall pain was reduced by 4.4 ± 2.8 points (NRS) at 3-months (n = 117) and at 12 months post-implant (n = 90), respectively (p < 0.0001). Substantial quality-of-life (EQ-5D-5L) improvement as assessed at last follow-up was also observed (n = 60). These results suggest that an implanted SCS device capable of combination therapy, while also enabled with patient-specific waveform optimization and stimulation field targeting capabilities, can enable highly effective pain relief and improve quality of life in patients suffering with chronic pain.
ABSTRACT
The Brief Pain Inventory (BPI) is a widely used pain measurement tool. There are 2 versions, the BPI Long Form (BPI-LF) and Short Form (BPI-SF), which share 2 core scales measuring pain severity and pain interference but which use different recall periods (24 hours vs. 1 week). To date, the BPI-SF has not been validated for use in Spain. This study investigated the psychometric properties of the BPI-SF Spanish version and compared results on the core scales between BPI-LF and BPI-SF. The data came from a 3-month observational study of 3,029 nononcologic patients managed in Spanish pain units. The BPI-SF's reliability, validity, and responsiveness were assessed. The effect of different recall periods was investigated by using intraclass correlation coefficients (ICCs) to determine the strength of correlation between BPI-LF and BPI-SF. The BPI-SF showed good reliability, with Cronbach's alphas of 0.931 for the severity and interference scales, which also discriminated well between patients reporting different levels of quality of life on EuroQol-5D dimensions (between group effect sizes [ESs] over 0.8). Substantial improvements were seen on both subscales after 3 months of treatment (ES of 1.76 for pain severity and 1.51 for pain interference). Recall period did not noticeably affect scores; ICCs (95% CI) between the long and short versions were 0.946 (0.938 to 0.954) and 0.929 (0.919 to 0.939) for the severity and interference subscales, respectively. The Spanish version of the BPI-SF is a valid and reliable instrument to measure pain severity and interference.
