scholarly journals The Influence of Missing Data on Disabilities in Patients Treated with High-Dose Spinal Cord Stimulation: A Tipping Point Sensitivity Analysis

2021 ◽  
Vol 10 (21) ◽  
pp. 4897
Author(s):  
Lisa Goudman ◽  
Geert Molenberghs ◽  
Rui V. Duarte ◽  
Maarten Moens

New waveforms have changed the field of Spinal Cord Stimulation (SCS) to optimize therapy outcomes, among which is High-Dose SCS (HD-SCS). Missing observations are often encountered when conducting clinical trials in this field. In this study, different approaches with varying assumptions were constructed to evaluate how conclusions may be influenced by these assumptions. The aim is to perform a tipping point sensitivity analysis to evaluate the influence of missing data on the overall conclusion regarding the effectiveness of HD-SCS on disability. Data from the Discover study were used, in which 185 patients with Failed Back Surgery Syndrome were included. Disability was evaluated before SCS and after 1, 3 and 12 months of HD-SCS. During the second, third and fourth visit, data from 130, 114 and 90 patients were available, respectively. HD-SCS resulted in a significant decrease in disability scores based on the analysis of observed data and with multiple imputations. The tipping point sensitivity analysis revealed that the shift parameter was 17. Thus, the conclusion concerning the time effect under a “missing at random” mechanism is robust when the shift parameter for the disability score is 17. From a clinical point of view, a shift of 17 points on disability is not very plausible. Therefore we tend to consider the conclusions drawn under “missing at random” as being robust.

2019 ◽  
Vol 24 ◽  
pp. 102087
Author(s):  
Sander De Groote ◽  
Lisa Goudman ◽  
Ronald Peeters ◽  
Bengt Linderoth ◽  
Peter Van Schuerbeek ◽  
...  

2020 ◽  
Vol 1;23 (1;1) ◽  
pp. 87-98 ◽  
Author(s):  
Ramsin Benyamin

Background: Therapeutic approaches to spinal cord stimulation (SCS) continue to evolve and improve patient outcomes in patients receiving SCS therapy secondary to failed back surgery syndrome. Objectives: The aim of this study was to evaluate pain relief and other patient outcomes of SCS using selected high-dose programming parameters. Study Design: This was a prospective cohort study. Setting: This study took place at 11 centers in North America. Methods: Forty-four SCS-naive patients underwent trialing, starting with 1,000 Hz frequency, 90 µs pulse width followed by 300 Hz frequency, 800 µs pulse width, if pain relief was inadequate. Patients with 50% or greater pain relief were eligible for permanent implantation. Patient’s pain rating, global impression of change, health-related quality of life, functional disability, satisfaction/ recommendation, stimulation perception, device programming, and adverse events were assessed at 3 months postimplant. Results: There were significant improvements from baseline in mean Numeric Rating Scale (NRS11) pain scores for overall pain (7.5 to 3.8; P < 0.01), back pain (7.2 to 3.4; P < 0.01), leg pain (7.2 to 3.1; P < 0.01), Oswestry Disability Index (ODI) score (51.5 to 32.1; P < 0.01), and European Quality of Life–Five Dimensions, version 5L score (EQ-5D-5L) (0.58 to 0.74; P < 0.01). Twentyeight of 32 patients (88%) had significant, favorable improvement in Patient Global Impression of Change (PGIC). Eighty-four percent of patients were “satisfied,” and 78.1% would “definitely” recommend SCS. Eighteen patients (56%) used 1,000 Hz frequency and 90 µs pulse width exclusively; these patients experienced mean NRS-11 overall pain score improvement of 4.7 points. Device-, therapy-, or procedure-related adverse events were experienced in 19 patients (40%, 19 of 48), and all events resolved without reoperation and were similar to those observed with traditional SCS systems. Limitations: There was no active or sham comparator group, and therefore the reported effects may not be solely attributable to therapy effects and may be related to other, nonspecific effects of SCS. Conclusions: Improvements in pain relief, PGIC, EQ-5D-5L, ODI, and patient satisfaction were all clinically relevant and statistically significant. Future studies are needed to understand how these high-dose parameters perform versus a standard comparator. Key words: Spinal cord stimulation, high-frequency electrical stimulation, failed back surgery syndrome, neurostimulation, prospective, nonrandomized study


2020 ◽  
Vol 9 (10) ◽  
pp. 3126
Author(s):  
Mats De Jaeger ◽  
Lisa Goudman ◽  
Koen Putman ◽  
Ann De Smedt ◽  
Philippe Rigoard ◽  
...  

Patients with Failed Back Surgery Syndrome (FBSS) report a considerably lower health- related quality of life (HRQoL), compared to the general population. Spinal cord stimulation (SCS) is an effective treatment to offer pain relief in those patients. Despite initial treatment success of SCS, its effect sometimes wears off over time. This study investigates the added value of high dose SCS (HD-SCS) in patients with unsatisfactory conventional SCS, from a quality of life perspective. Seventy-eight FBSS patients who were treated with conventional SCS that failed to provide pain relief, were recruited in 15 centers. HRQoL was assessed before converting to HD-SCS (baseline) and three times after converting to HD-SCS using the EuroQol-5D-3L. Quality adjusted life years (QALY) were calculated and compared with conventional SCS. An overall significant increase over time was seen in utility values of the EQ5D-3L, as the mean value at baseline 0.283 (±0.21) increased to 0.452 (±0.29) at 12 months of HD-SCS. This average increase in utility coincides with an average increase of 0.153 (±0.24) QALY’s in comparison to continued conventional SCS. Besides the potential of HD-SCS to salvage patients with failed responses to conventional SCS, this treatment seems to be a more efficient treatment than conventional SCS.


Pain ◽  
2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Lisa Goudman ◽  
Ann De Smedt ◽  
Sam Eldabe ◽  
Philippe Rigoard ◽  
Bengt Linderoth ◽  
...  

2021 ◽  
Vol 21 (9) ◽  
pp. S46
Author(s):  
Ram Haddas ◽  
Isador H. Lieberman ◽  
Donna D. Ohnmeiss ◽  
Ralph F. Rashbaum

Author(s):  
Shelby Sabourin ◽  
Justin Tram ◽  
Breanna L. Sheldon ◽  
Julie G. Pilitsis

OBJECTIVE Minimal clinically important difference (MCID) thresholds for a limited number of outcome metrics were previously defined for patients with failed back surgery syndrome (FBSS) at 6 months after spinal cord stimulation (SCS). This study aimed to further define MCID values for pain and disability outcomes. Additionally, the authors established 1-year MCID values for outcome measures with previously defined metrics commonly used to assess SCS efficacy. METHODS Preoperative and 1-year postoperative outcomes were collected from 114 patients who received SCS therapy for FBSS, complex regional pain syndrome, and neuropathic pain. MCID values were established for the numerical rating scale (NRS), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), McGill Pain Questionnaire (MPQ), and Pain Catastrophizing Scale (PCS). Four established anchor-based methods were utilized to compute MCID values with two anchored questions: “Are you satisfied with SCS therapy?” and “Would you have SCS surgery again?” For each question, patients were categorized as responders if they answered “yes” or as nonresponders if they responded “no.” The methodologies utilized to compute MCID scores included the average change method, minimum detectable change approach, change difference calculation, and receiver operating characteristic (ROC) analysis. Area under the ROC curve (AUC) analysis has been shown to inform the accuracy at which the MCID value can distinguish responders from nonresponders and was analyzed for each instrument. RESULTS For the first time, ranges of MCID values after SCS were established for MPQ (1–2.3) and PCS (1.9–13.6). One-year MCID values were defined for all indications: NRS (range 0.9–2.7), ODI (3.5–6.9), and BDI (2–5.9). AUC values were significant for NRS (0.78, p < 0.001), ODI (0.71, p = 0.003), MPQ (0.74, p < 0.001), and PCS (0.77, p < 0.001), indicating notable accuracy for distinguishing satisfied patients. CONCLUSIONS This was the first study to successfully determine MCID values for two prominent instruments, MPQ and PCS, used to assess pain after SCS surgery. Additionally, previously established MCID values for ODI, BDI, and the visual analog scale for patients with FBSS at 6 months after treatment were explored at 12 months for the most common indications for SCS. These data may better inform physicians of patient response to and success with SCS therapy.


PLoS ONE ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. e0228306
Author(s):  
Peter A. Pahapill ◽  
Guangyu Chen ◽  
Elsa V. Arocho-Quinones ◽  
Andrew S. Nencka ◽  
Shi-Jiang Li

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