Five-Year Longitudinal Follow-Up of Restorative Neurostimulation Shows Durability of Effectiveness in Patients With Refractory Chronic Low Back Pain Associated With Multifidus Muscle Dysfunction.

BACKGROUND: Adults with refractory, mechanical chronic low back pain associated with impaired neuromuscular control of the lumbar multifidus muscle have few treatment options that provide long-term clinical benefit. This study hypothesized that restorative neurostimulation, a rehabilitative treatment that activates the lumbar multifidus muscles to overcome underlying dysfunction, is safe and provides relevant and durable clinical benefit to patients with this specific etiology. MATERIALS AND METHODS: In this prospective five-year longitudinal follow-up of the ReActiv8-B pivotal trial, participants (N = 204) had activity-limiting, moderate-to-severe, refractory, mechanical chronic low back pain, a positive prone instability test result indicating impaired multifidus muscle control, and no indications for spine surgery. Low back pain intensity (10-cm visual analog scale [VAS]), disability (Oswestry Disability Index), and quality of life (EuroQol's "EQ-5D-5L" index) were compared with baseline and following the intent-to-treat principle, with a supporting mixed-effects model for repeated measures that accounted for missing data. RESULTS: At five years (n = 126), low back pain VAS had improved from 7.3 to 2.4 cm (-4.9; 95% CI, -5.3 to -4.5 cm; p < 0.0001), and 71.8% of participants had a reduction of ≥50%. The Oswestry Disability Index improved from 39.1 to 16.5 (-22.7; 95% CI, -25.4 to -20.8; p < 0.0001), and 61.1% of participants had reduction of ≥20 points. The EQ-5D-5L index improved from 0.585 to 0.807 (0.231; 95% CI, 0.195-0.267; p < 0.0001). Although the mixed-effects model attenuated completed-case results, conclusions and statistical significance were maintained. Of 52 subjects who were on opioids at baseline and had a five-year visit, 46% discontinued, and 23% decreased intake. The safety profile compared favorably with neurostimulator treatments for other types of back pain. No lead migrations were observed. CONCLUSION: Over a five-year period, restorative neurostimulation provided clinically substantial and durable benefits with a favorable safety profile in patients with refractory chronic low back pain associated with multifidus muscle dysfunction. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT02577354; registration date: October 15, 2016; principal investigator: Christopher Gilligan, MD, Brigham and Women's Hospital, Boston, MA, USA. The study was conducted in Australia (Broadmeadow, New South Wales; Noosa Heads, Queensland; Welland, South Australia; Clayton, Victoria), Belgium (Sint-Niklaas; Wilrijk), The Netherlands (Rotterdam), UK (Leeds, London, Middlesbrough), and USA (La Jolla, CA; Santa Monica, CA; Aurora, CO; Carmel, IN; Indianapolis, IN; Kansas City, KS; Boston, MA; Royal Oak, MI; Durham, NC; Winston-Salem, NC; Cleveland, OH; Providence, RI; Spartanburg, SC; Spokane, WA; Charleston, WV).

'It was a joint plan we worked out together'. How the I-WOTCH programme enabled people with chronic non-malignant pain to taper their opioids: a process evaluation.

BACKGROUND: The Improving the Wellbeing of people with Opioid Treated CHronic pain (I-WOTCH) randomised controlled trial found that a group-based educational intervention to support people using strong opioids for chronic non-malignant pain helped a significant proportion of people to stop or decrease opioid use with no increase in pain-related disability. We report a linked process evaluation of the group-based intervention evaluated in comparison to a usual-care control group that received a self-help booklet and relaxation CD. METHODS: We interviewed 18 intervention facilitators, and 20 intervention and 20 control participants who had chronic non-malignant pain and were recruited from general (family) practices in the UK. Quantitative data included change mechanism questions on the trial questionnaires which explored motivation, expectations and self-efficacy. Fidelity was assessed by listening to a sample of audio-recorded group sessions and nurse consultations. Quantitative and qualitative data were integrated using 'follow a thread' and a mixed-methods matrix. FINDINGS: Four overarching themes emerged: (1) the right time to taper, (2) the backdrop of a life with chronic pain, (3) needing support and (4) the benefits of being in a group. Delivery fidelity was good, adherence (83%) and competence (79%) across a range of intervention groups. Staff delivering the intervention found three typical responses to the intervention: resistance, open to trying and feeling it was not the right time. The group experience was important to those in the intervention arm. It provided people with a forum in which to learn about the current thinking about opioid usage and its effects. It also gave them examples of how feasible or personally relevant coming off opioids might be. CONCLUSION: The process evaluation data showed that the I-WOTCH intervention was well delivered, well received and useful for most interviewees. Being 'the right time' to taper and having support throughout tapering, emerged as important factors within the context of living with chronic pain. TRIAL REGISTRATION NUMBER: ISRCTN49470934.

Role of patient selection and trial stimulation for spinal cord stimulation therapy for chronic non-cancer pain: a comprehensive narrative review.

BACKGROUND/IMPORTANCE: Patient selection for spinal cord stimulation (SCS) therapy is crucial and is traditionally performed with clinical selection followed by a screening trial. The factors influencing patient selection and the importance of trialing have not been systematically evaluated. OBJECTIVE: We report a narrative review conducted to synthesize evidence regarding patient selection and the role of SCS trials. EVIDENCE REVIEW: Medline, EMBASE and Cochrane databases were searched for reports (any design) of SCS in adult patients, from their inception until March 30, 2022. Study selection and data extraction were carried out using DistillerSR. Data were organized into tables and narrative summaries, categorized by study design. Importance of patient variables and trialing was considered by looking at their influence on the long-term therapy success. FINDINGS: Among 7321 citations, 201 reports consisting of 60 systematic reviews, 36 randomized controlled trials (RCTs), 41 observational studies (OSs), 51 registry-based reports, and 13 case reports on complications during trialing were included. Based on RCTs and OSs, the median trial success rate was 72% and 82%, and therapy success was 65% and 61% at 12 months, respectively. Although several psychological and non-psychological determinants have been investigated, studies do not report a consistent approach to patient selection. Among psychological factors, untreated depression was associated with poor long-term outcomes, but the effect of others was inconsistent. Most RCTs except for chronic angina involved trialing and only one RCT compared patient selection with or without trial. The median (range) trial duration was 10 (0-30) and 7 (0-56) days among RCTs and OSs, respectively. CONCLUSIONS: Due to lack of a consistent approach to identify responders for SCS therapy, trialing complements patient selection to exclude patients who do not find the therapy helpful and/or intolerant of the SCS system. However, more rigorous and large studies are necessary to better evaluate its role.

Evidence-based consensus guidelines on patient selection and trial stimulation for spinal cord stimulation therapy for chronic non-cancer pain.

Spinal cord stimulation (SCS) has demonstrated effectiveness for neuropathic pain. Unfortunately, some patients report inadequate long-term pain relief. Patient selection is emphasized for this therapy; however, the prognostic capabilities and deployment strategies of existing selection techniques, including an SCS trial, have been questioned. After approval by the Board of Directors of the American Society of Regional Anesthesia and Pain Medicine, a steering committee was formed to develop evidence-based guidelines for patient selection and the role of an SCS trial. Representatives of professional organizations with clinical expertize were invited to participate as committee members. A comprehensive literature review was carried out by the steering committee, and the results organized into narrative reports, which were circulated to all the committee members. Individual statements and recommendations within each of seven sections were formulated by the steering committee and circulated to members for voting. We used a modified Delphi method wherein drafts were circulated to each member in a blinded fashion for voting. Comments were incorporated in the subsequent revisions, which were recirculated for voting to achieve consensus. Seven sections with a total of 39 recommendations were approved with 100% consensus from all the members. Sections included definitions and terminology of SCS trial; benefits of SCS trial; screening for psychosocial characteristics; patient perceptions on SCS therapy and the use of trial; other patient predictors of SCS therapy; conduct of SCS trials; and evaluation of SCS trials including minimum criteria for success. Recommendations included that SCS trial should be performed before a definitive SCS implant except in anginal pain (grade B). All patients must be screened with an objective validated instrument for psychosocial factors, and this must include depression (grade B). Despite some limitations, a trial helps patient selection and provides patients with an opportunity to experience the therapy. These recommendations are expected to guide practicing physicians and other stakeholders and should not be mistaken as practice standards. Physicians should continue to make their best judgment based on individual patient considerations and preferences.

Efficacy, safety, and tolerability of antidepressants for pain in adults: overview of systematic reviews.

OBJECTIVE: To provide a comprehensive overview of the efficacy, safety, and tolerability of antidepressants for pain according to condition. DESIGN: Overview of systematic reviews. DATA SOURCES: PubMed, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials from inception to 20 June 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Systematic reviews comparing any antidepressant with placebo for any pain condition in adults. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted data. The main outcome measure was pain; for headache disorders it was frequency of headaches. Continuous pain outcomes were converted into a scale of 0 (no pain) to 100 (worst pain) and were presented as mean differences (95% confidence intervals). Dichotomous outcomes were presented as risk ratios (95% confidence intervals). Data were extracted from the time point closest to the end of treatment. When end of treatment was too variable across trials in a review, data were extracted from the outcome or time point with the largest number of trials and participants. Secondary outcomes were safety and tolerability (withdrawals because of adverse events). Findings were classified from each comparison as efficacious, not efficacious, or inconclusive. Certainty of evidence was assessed with the grading of recommendations assessment, development, and evaluation framework. RESULTS: 26 reviews (156 unique trials and >25 000 participants) were included. These reviews reported on the efficacy of eight antidepressant classes covering 22 pain conditions (42 distinct comparisons). No review provided high certainty evidence on the efficacy of antidepressants for pain for any condition. 11 comparisons (nine conditions) were found where antidepressants were efficacious, four with moderate certainty evidence: serotonin-norepinephrine reuptake inhibitors (SNRIs) for back pain (mean difference -5.3, 95% confidence interval -7.3 to -3.3), postoperative pain (-7.3, -12.9 to -1.7), neuropathic pain (-6.8, -8.7 to -4.8), and fibromyalgia (risk ratio 1.4, 95% confidence interval 1.3 to 1.6). For the other 31 comparisons, antidepressants were either not efficacious (five comparisons) or the evidence was inconclusive (26 comparisons). CONCLUSIONS: Evidence of efficacy of antidepressants was found in 11 of the 42 comparisons included in this overview of systematic reviews-seven of the 11 comparisons investigated the efficacy of SNRIs. For the other 31 comparisons, antidepressants were either inefficacious or evidence on efficacy was inconclusive. The findings suggest that a more nuanced approach is needed when prescribing antidepressants for pain conditions. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022311073.

Effectiveness and Safety of Intrathecal Drug Delivery Systems for the Management of Cancer Pain: A Systematic Review and Meta-Analysis.

OBJECTIVES: Intrathecal drug delivery systems (IDDS) and spinal cord stimulation (SCS) have been proposed and assessed for the management of cancer pain; however, such treatments remain underused. We conducted a systematic review to evaluate the effectiveness and safety of IDDS and SCS for cancer pain. MATERIALS AND METHODS: Electronic databases MEDLINE, CENTRAL, EMBASE, and WikiStim were searched from 1988 to March 2021. Randomized controlled trials and observational studies of adults with pain related to cancer or its treatment who received an implantable IDDS or SCS were eligible for inclusion. The primary outcome of the review was change in pain intensity from baseline to the last available follow-up, measured using a visual analog scale or numerical rating scale. The protocol for this review is registered on PROSPERO (CRD42021240717). RESULTS: A total of 22 studies (24 reports) included a total of 3043 participants who received either IDDS or SCS for cancer pain. Eight studies reporting data for 405 participants with an IDDS could be included in the meta-analysis of pain intensity that showed a statistically significant reduction at the latest posttreatment follow-up time compared with baseline (mean difference [MD], -3.31; 95% CI, -4.18 to -2.45; p < 0.001). Six studies reporting data for 325 participants with an IDDS could be included in the meta-analysis of pain intensity that showed a statistically significant reduction up to one month after treatment compared with baseline (MD, -3.53; 95% CI, -4.06 to -3.00; p < 0.001). A meta-analysis including studies of participants with either an IDDS or an SCS device showed similar results. Improvements in other outcomes following implantation of IDDS also were observed. Postdural puncture headache was the most reported complication, whereas urinary retention, nausea, and vomiting were commonly reported side effects. CONCLUSION: Our findings suggest that IDDS is effective in reducing pain intensity for patients with cancer pain when compared with pretreatment.

Long-Term Outcomes of Restorative Neurostimulation in Patients With Refractory Chronic Low Back Pain Secondary to Multifidus Dysfunction: Two-Year Results of the ReActiv8-B Pivotal Trial.

BACKGROUND: Impaired neuromuscular control and degeneration of the multifidus muscle have been linked to the development of refractory chronic low back pain (CLBP). An implantable restorative-neurostimulator system can override the underlying multifidus inhibition by eliciting episodic, isolated contractions. The ReActiv8-B randomized, active-sham-controlled trial provided effectiveness and safety evidence for this system, and all participants received therapeutic stimulation from four months onward. OBJECTIVE: This study aimed to evaluate the two-year effectiveness of this restorative neurostimulator in patients with disabling CLBP secondary to multifidus muscle dysfunction and no indications for spine surgery. MATERIALS AND METHODS: Open-label follow-up of 204 participants implanted with a restorative neurostimulation system (ReActiv8, Mainstay Medical, Dublin, Ireland) was performed. Pain intensity (visual analog scale [VAS]), disability (Oswestry disability index [ODI]), quality-of-life (EQ-5D-5L), and opioid intake were assessed at baseline, six months, one year, and two years after activation. RESULTS: At two years (n = 156), the proportion of participants with ≥50% CLBP relief was 71%, and 65% reported CLBP resolution (VAS ≤ 2.5 cm); 61% had a reduction in ODI of ≥20 points, 76% had improvements of ≥50% in VAS and/or ≥20 points in ODI, and 56% had these substantial improvements in both VAS and ODI. A total of 87% of participants had continued device use during the second year for a median of 43% of the maximum duration, and 60% (34 of 57) had voluntarily discontinued (39%) or reduced (21%) opioid intake. CONCLUSIONS: At two years, 76% of participants experienced substantial, clinically meaningful improvements in pain, disability, or both. These results provide evidence of long-term effectiveness and durability of restorative neurostimulation in patients with disabling CLBP, secondary to multifidus muscle dysfunction. CLINICAL TRIAL REGISTRATION: The study is registered on clinicaltrials.gov with identifier NCT02577354.

Gradation of Clinical Holistic Response as New Composite Outcome to Evaluate Success in Spinal Cord Stimulation Studies for Pain.

INTRODUCTION: The most prominent outcome measurement in the field of neuromodulation is pain relief. Nevertheless, the number of studies that rely on composite outcomes has increased. The aims of this study are twofold: (1) to evaluate which measures are important to include in a composite outcome and (2) to develop this new composite outcome to evaluate the degree of being a clinical holistic responder with a corresponding minimal clinical important difference (MCID). MATERIALS AND METHODS: Data from patients with persistent spinal pain syndrome type 2 treated with High-Dose Spinal Cord Stimulation (HD-SCS) were used. Pain intensity for low back and leg pain, disability, health-related quality of life, medication use, and patient satisfaction were measured at baseline and after 12 months of HD-SCS. Exploratory and Confirmatory Factor Analyses were used to evaluate which measures should be included in the composite outcome. Anchor-based and distribution-based methods were applied to determine the MCID of the newly developed outcome measurement. RESULTS: A three-factor model was the most appropriate for this data set, in which leg pain intensity, EQ5D VAS, and disability had the largest loading on these factors. A clinical holistic outcome was created with a total score ranging from 0 (=better [no pain, no disability, and perfect health status]) to 300 (=worse [maximal pain, maximal disability, and worst health status]). The MCID value based on an absolute change score from baseline up to 12 months of HD-SCS was 87.97. When calculating with percentage changes, a MCID value of 48.4% was revealed. CONCLUSIONS: This new composite outcome evaluating the degree of deviation from being a holistic responder is a step toward a meaningful, overall outcome assessment for patients who are treated with SCS. Further studies to evaluate the psychometric properties and the generalizability toward other patient populations still need to be performed.

Ziconotide for the Management of Cancer Pain: A Budget Impact Analysis.

OBJECTIVES: Recent recommendations on starting dose, smaller dose increments, and longer intervals between dose increase have the potential to increase the safety of ziconotide administration in addition to improving its value for money. Ziconotide is not routinely commissioned in England, with one of the concerns being whether it represents the best use of resources. The aim of this project is to conduct a budget impact analysis to estimate the costs or savings associated with the changes in ziconotide dosage in addition to its use in combination with morphine for the management of cancer pain. MATERIALS AND METHODS: An open, Markov-like cohort decision analytic model was developed to estimate the budget impact of ziconotide in combination with morphine (ziconotide combination therapy) vs morphine monotherapy through intrathecal drug delivery (ITDD) for the management of cancer pain. The perspective adopted was that of the UK National Health Service, with a five-year time horizon. Sensitivity analyses were conducted to evaluate different scenarios. RESULTS: Ziconotide combination therapy was more expensive than treatment with morphine monotherapy. The total costs of ziconotide combination therapy and morphine monotherapy for the first year were £395,748 and £136,628 respectively. The estimated five-year cumulative budget impact of treatment with ziconotide combination therapy for the five-year time horizon was £2,487,539, whereas that of morphine monotherapy was £913,804. The additional costs in any of the first five years are below the resource impact significance level of £1 million for medical technologies in England. CONCLUSIONS: The results of this budget impact analysis suggest that although a combination of intrathecal ziconotide in combination with morphine is associated with higher costs to the health care system in England, the incremental costs are not significant. Routine commissioning of ziconotide alone or in combination with morphine would provide an alternative for a population with limited ITDD treatment options.

Three-Year Durability of Restorative Neurostimulation Effectiveness in Patients With Chronic Low Back Pain and Multifidus Muscle Dysfunction.

BACKGROUND: Restorative neurostimulation is a rehabilitative treatment for patients with refractory chronic low back pain (CLBP) associated with dysfunction of the lumbar multifidus muscle resulting in impaired neuromuscular control. The ReActiv8-B randomized, sham-controlled trial provided evidence of the effectiveness and safety of an implanted, restorative neurostimulator. The two-year analysis previously published in this journal demonstrated accrual of clinical benefits and long-term durability. OBJECTIVE: Evaluation of three-year effectiveness and safety in patients with refractory, disabling CLBP secondary to multifidus muscle dysfunction and no indications for spine surgery. MATERIALS AND METHODS: Prospective, observational follow-up of the 204 implanted trial participants. Low back pain visual analog scale (VAS), Oswestry Disability Index (ODI), EuroQol quality of life survey, and opioid intake were assessed at baseline, six months, and one, two, and three years after activation. The mixed-effects model repeated measures approach was used to provide implicit imputations of missing data for continuous outcomes and multiple imputation for proportion estimates. RESULTS: Data were collected from 133 participants, and 16 patients missed their three-year follow-up because of coronavirus disease restrictions but remain available for future follow-up. A total of 62% of participants had a ≥ 70% VAS reduction, and 67% reported CLBP resolution (VAS ≤ 2.5cm); 63% had a reduction in ODI of ≥ 20 points; 83% had improvements of ≥ 50% in VAS and/or ≥ 20 points in ODI, and 56% had these substantial improvements in both VAS and ODI. A total of 71% (36/51) participants on opioids at baseline had voluntarily discontinued (49%) or reduced (22%) opioid intake. The attenuation of effectiveness in the imputed (N = 204) analyses was relatively small and did not affect the statistical significance and clinical relevance of these results. The safety profile remains favorable, and no lead migrations have been observed to date. CONCLUSION: At three years, 83% of participants experienced clinically substantial improvements in pain, disability, or both. The results confirm the long-term effectiveness, durability, and safety of restorative neurostimulation in patients with disabling CLBP associated with multifidus muscle dysfunction. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT02577354.

Rationale and Recent Advances in Targeted Drug Delivery for Cancer Pain: Is It Time to Change the Paradigm?

BACKGROUND: Cancer pain prevalence remains high with more than 60% of patients with advanced cancer experiencing cancer-related pain. The undertreatment of pain due to concerns of opioid dependence or diversion, as well as the potential effect of opioids on tumor neogenesis, add to the suffering among cancer populations. OBJECTIVES: The aim of this narrative review was to assess evidence on the effectiveness, safety, cost-effectiveness, and advances of Intrathecal (IT) Drug Delivery Systems (IDDS) for the management of cancer pain. STUDY DESIGN: The present review was performed by searching for articles indexed in PubMed, MEDLINE, SciELO, Google Scholar, and Scopus. METHODS: Studies were included if they investigated patients with chronic cancer-related pain treated with IDDS and assessed experienced pain. We performed a narrative synthesis. RESULTS: IDDS have demonstrated efficacy in relieving cancer pain even in the challenging treatment of head and neck cancer pain. IDDS is also associated with a large reduction in serum opioid concentrations limiting adverse effects. When combined with other analgesics commonly used in the spinal space, but not systemically, pain relief may be dramatically improved. Advances in IT drug diffusion, including mixtures created with pharmaceutical compounding, improve the safety and accuracy of this therapy. IDDS is cost-effective and safe yet remains underutilized in this patient population. LIMITATIONS: Despite numerous clinical studies, only a small number of randomized trials have been conducted to evaluate the effectiveness of IDDS for cancer pain. CONCLUSIONS: This article presents an overview of the current state of evidence on the effectiveness, safety, cost-effectiveness, and advances of IDDS for the management of cancer pain. Despite current evidence, IDDS remains underutilized for people with cancer pain. Potential areas to facilitate its use are discussed. A shift in the paradigm of cancer pain treatment should be considered given the undertreatment rate, lack of benefits, and considerable risks associated with oral opioid medication in many patients who suffer from chronic cancer pain.

Cauda equina syndrome after unilateral medial branch blocks of the lower lumbar zygapophyseal joints.

Medial branch blockade of the lumbar facet joints is widely performed and generally accepted as a safe intervention. We present a case of neurological damage following a medial branch blockade with local anesthetic and steroid. A patient suffering from chronic low back pain radiating to the buttocks and thighs underwent nine medial branch blockades over a few years. Three months after successful back surgery to remove a herniated L2-3 disk, the pain recurred, and left L3-4 , L4-5, and L5 -S1  medial branch blocks were performed under fluoroscopy. Immediately following the procedure, the patient developed paraparesis in both legs, loss of pinprick but preserved fine touch sensation, proprioception, and sphincter sensory and motor function. MRI showed ischemic lesions of the cauda equina. Direct needle trauma was discounted as a cause, due to the bilateral neurological deficit, plus the lack of pain during the procedure. Particulate steroid preparations can form aggregates, which may embolize and block small terminal arteries, causing neurological damage. Although the patient received nine sets of injections uneventfully during the previous 36 months, this procedure took place 3 months following spinal surgery. This rare, but catastrophic case of cauda equina syndrome occurred following L3-4 , L4-5 , and L5 -S1  medial branch blockades 3 months after spinal surgery, which is believed to be caused by accidental intra-arterial injection of particulate methylprednisolone, with consequent aggregates causing blockage and ensuing ischemia. Therefore we suggest particulate steroid preparations should not be used in axial spinal injection.

Development and testing of an opioid tapering self-management intervention for chronic pain: I-WOTCH.

OBJECTIVES: To describe the design, development and pilot of a multicomponent intervention aimed at supporting withdrawal of opioids for people with chronic non-malignant pain for future evaluation in the Improving the Wellbeing of people with Opioid Treated CHronic pain (I-WOTCH) randomised controlled trial. DESIGN: The I-WOTCH intervention draws on previous literature and collaboration with stakeholders (patient and public involvement). Intervention mapping and development activities of Behaviour Change Taxonomy are described. SETTING: The intervention development was conducted by a multidisciplinary team with clinical, academic and service user perspectives. The team had expertise in the development and testing of complex health behaviour interventions, opioid tapering and pain management in primary and secondary care, I.T programming, and software development-to develop an opioid tapering App. PARTICIPANTS: The I-WOTCH trial participants are adults (18 years and over) with chronic non-malignant pain using strong opioids for at least 3 months and on most days in the preceding month. OUTCOMES: A multicomponent self-management support package to help people using opioids for chronic non-malignant pain reduce opioid use. INTERVENTIONS AND RESULTS: Receiving information on the impact of long-term opioid use, and potential adverse effects were highlighted as important facilitators in making the decision to reduce opioids. Case studies of those who have successfully stopped taking opioids were also favoured as a facilitator to reduce opioid use. Barriers included the need for a 'trade-off to fill the deficit of the effect of the drug'. The final I-WOTCH intervention consists of an 8-10 week programme incorporating: education; problem-solving; motivation; group and one to one tailored planning; reflection and monitoring. A detailed facilitator manual was developed to promote consistent delivery of the intervention across the UK. CONCLUSIONS: We describe the development of an opioid reduction intervention package suitable for testing in the I-WOTCH randomised controlled trial. TRIAL REGISTRATION NUMBER: ISRCTN49470934.

The impact of the COVID-19 pandemic on patients awaiting spinal cord stimulation surgery in the United Kingdom: a multi-centre patient survey.

INTRODUCTION: Spinal cord stimulation (SCS) is a recommended treatment for chronic refractory neuropathic pain. During the COVID-19 pandemic, elective procedures have been postponed indefinitely both to provide capacity to deal with the emergency caseload and to avoid exposure of elective patients to COVID-19. This survey aimed to explore the effect of the pandemic on chronic pain in this group and the views of patients towards undergoing SCS treatment when routine services should resume. METHODS: This was a prospective, multi-centre telephone patient survey that analysed data from 330 patients with chronic pain who were on an SCS waiting list. Questions focussed on severity of pain, effect on mental health, medication consumption and reliance on support networks during the COVID-19 pandemic. Views towards undergoing SCS therapy were also ascertained. Counts and percentages were generated, and chi-square tests of independence explored the impact of COVID-19 risk (very high, high, low) on survey responses. RESULTS: Pain, mental health and patient's ability to self-manage pain deteriorated in around 47%, 50% and 38% of patients, respectively. Some patients reported increases in pain medication consumption (37%) and reliance on support network (41%). Patients showed a willingness to attend for COVID-19 testing (92%), self-isolate prior to SCS (94%) and undergo the procedure as soon as possible (76%). CONCLUSION: Our findings suggest that even during the COVID-19 pandemic, there remains a strong clinical need for patients with chronic pain identified as likely SCS responders to be treated quickly. The current prioritisation of new SCS at category 4 (delayed more than 3 months) is challenged judging by this national survey. These patients are awaiting SCS surgery to relieve severe intractable neuropathic pain. A priority at category 3 (delayed up to 3 months) or in some selected cases, at category 2 are the appropriate priority categories.

Durability of the Therapeutic Effect of Restorative Neurostimulation for Refractory Chronic Low Back Pain.

OBJECTIVES: The purpose of the ongoing follow-up of ReActiv8-A clinical trial is to document the longitudinal benefits of episodic stimulation of the dorsal ramus medial branch and consequent contraction of the lumbar multifidus in patients with refractory mechanical chronic low back pain (CLBP). We report the four-year outcomes of this trial. MATERIALS AND METHODS: ReActiv8-A is a prospective, single-arm trial performed at nine sites in the United Kingdom, Belgium, and Australia. Eligible patients had disabling CLBP (low back pain Numeric Rating Scale [NRS] ≥6; Oswestry Disability Index [ODI] ≥25), no indications for spine surgery or spinal cord stimulation, and failed conventional management including at least physical therapy and medications for low back pain. Fourteen days postimplantation, stimulation parameters were programmed to elicit strong, smooth contractions of the multifidus, and participants were given instructions to activate the device for 30-min stimulation-sessions twice daily. Annual follow-up through four years included collection of NRS, ODI, and European Quality of Life Score on Five Dimensions (EQ-5D). Background on mechanisms, trial design, and one-year outcomes were previously described. RESULTS: At baseline (N = 53) (mean ± SD) age was 44 ± 10 years; duration of back pain was 14 ± 11 years, NRS was 6.8 ± 0.8, ODI 44.9 ± 10.1, and EQ-5D 0.434 ± 0.185. Mean improvements from baseline were statistically significant (p < 0.001) and clinically meaningful for all follow-ups. Patients completing year 4 follow-up, reported mean (±standard error of the mean) NRS: 3.2 ± 0.4, ODI: 23.0 ± 3.2, and EQ-5D: 0.721 ± 0.035. Moreover, 73% of participants had a clinically meaningful improvement of ≥2 points on NRS, 76% of ≥10 points on ODI, and 62.5% had a clinically meaningful improvement in both NRS and ODI and 97% were (very) satisfied with treatment. CONCLUSIONS: In participants with disabling intractable CLBP who receive long-term restorative neurostimulation, treatment satisfaction remains high and improvements in pain, disability, and quality-of-life are clinically meaningful and durable through four years.

Resource Use and Cost of Subcutaneous Nerve Stimulation Versus Optimized Medical Management in Patients With Failed Back Surgery Syndrome: An Analysis of the SubQStim Study.

OBJECTIVES: To undertake a detailed healthcare resource use and cost analysis of the SubQStim study, which randomized patients with failed back surgery syndrome (FBSS) with low back pain to receive subcutaneous nerve field stimulation in combination with optimized medical management (treatment) or optimized medical management alone (control). MATERIALS AND METHODS: Patient-level data from the SubQStim study were used to present descriptive analyses of healthcare resource use and estimated costs for pain medication, healthcare visits, adverse events, and device acquisition/implantation. A United Kingdom National Health Service perspective was adopted, using cost data from national tariffs, drug and device prices, and social care cost studies. Results were calculated as the mean cost per patient over the nine-month follow-up period. RESULTS: Mean cost per patient was £18,403 in the treatment group versus £1613 in the control group. Almost 90% of the cost in the treatment group consisted of device acquisition/implantation. Higher adverse event costs were observed for patients in the treatment group, but lower costs were observed for pain medication and healthcare visits. Over nine months, opioid use decreased in the treatment group and increased in the control group. Enrolment and follow-up were terminated early in the clinical study, leading to substantial between-patient variability in each cost category. CONCLUSIONS: Subcutaneous nerve field stimulation has the potential to offset the initial costs of the device by reducing analgesic medication and the number of healthcare visits in FBSS patients, alongside potential gains in health-related quality of life. There remains uncertainty in long-term costs and cost-effectiveness of stimulation and longer-term follow-up analyses are needed.

Persistent Spinal Pain Syndrome: A Proposal for Failed Back Surgery Syndrome and ICD-11.

OBJECTIVE: For many medical professionals dealing with patients with persistent pain following spine surgery, the term Failed back surgery syndrome (FBSS) as a diagnostic label is inadequate, misleading, and potentially troublesome. It misrepresents causation. Alternative terms have been suggested, but none has replaced FBSS. The International Association for the Study of Pain (IASP) published a revised classification of chronic pain, as part of the new International Classification of Diseases (ICD-11), which has been accepted by the World Health Organization (WHO). This includes the term Chronic pain after spinal surgery (CPSS), which is suggested as a replacement for FBSS. METHODS: This article provides arguments and rationale for a replacement definition. In order to propose a broadly applicable yet more precise and clinically informative term, an international group of experts was established. RESULTS: 14 candidate replacement terms were considered and ranked. The application of agreed criteria reduced this to a shortlist of four. A preferred option-Persistent spinal pain syndrome-was selected by a structured workshop and Delphi process. We provide rationale for using Persistent spinal pain syndrome and a schema for its incorporation into ICD-11. We propose the adoption of this term would strengthen the new ICD-11 classification. CONCLUSIONS: This project is important to those in the fields of pain management, spine surgery, and neuromodulation, as well as patients labeled with FBSS. Through a shift in perspective, it could facilitate the application of the new ICD-11 classification and allow clearer discussion among medical professionals, industry, funding organizations, academia, and the legal profession.