Pain (chronic neuropathic or ischaemic) - spinal cord stimulation: appraisal consultation document
NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE
Appraisal Consultation Document
Spinal cord stimulation for chronic pain of neuropathic or ischaemic origin
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The Department of Health has asked the National Institute for Health and Clinical Excellence (NICE or the Institute) to conduct a multiple technology appraisal of spinal cord stimulation for chronic pain of neuropathic or ischaemic origin and provide guidance on its use to the NHS in England and Wales. The Appraisal Committee has had its first meeting to consider both the evidence submitted and the views put forward by non-manufacturer consultees and commentators, and by the clinical specialist and patient expert representatives nominated for this appraisal by non-manufacturer consultees and commentators. The Committee has developed preliminary recommendations on the use of spinal cord stimulation for chronic pain of neuropathic or ischaemic origin. This document has been prepared for consultation with the formal consultees. It summarises the evidence and views that have been considered and sets out the preliminary recommendations developed by the Committee. The Institute is now inviting comments from the formal consultees in the appraisal process (the consultees for this appraisal are listed on the NICE website, www.nice.org.uk). This document should be read in conjunction with the evidence base for this appraisal (the evaluation report) which is available from www.nice.org.uk Note that this document does not constitute the Institute's formal guidance on this technology. The recommendations made in section 1 are preliminary and may change after consultation. The process the Institute will follow after the consultation period is summarised below. For further details, see the 'Guide to the technology appraisal process' (this document is available on the Institute's website, www.nice.org.uk).
The key dates for this appraisal are: Closing date for comments: 4 July 2008 Second Appraisal Committee meeting: 17 July 2008 Details of membership of the Appraisal Committee are given in appendix A, and a list of the sources of evidence used in the preparation of this document is given in appendix B. |
| Note that this document does not constitute the Institute's formal guidance on this technology. The recommendations made in Section 1 are preliminary and may change after consultation. |
| 1 | Appraisal Committee's preliminary recommendations |
| This guidance provides recommendations for the use of spinal cord stimulation for the following chronic pain conditions: failed back surgery syndrome, complex regional pain syndrome, critical limb ischaemia and refractory angina. | |
| 1.1 | Spinal cord stimulation is recommended as a treatment option for adults with failed back surgery syndrome who continue to experience chronic pain (measuring at least 50 mm on a 0-100 mm visual analogue scale) for at least 6 months after surgery despite adequate standard care, and who have had a successful trial of stimulation (as defined in recommendation 1.4). |
| 1.2 | Spinal cord stimulation is not recommended as a treatment option for adults with complex regional pain syndrome, critical limb ischaemia or refractory angina except in the context of research as part of a clinical trial. Such research should be designed to generate robust evidence about the durability of the benefits of spinal cord stimulation (including pain relief and quality of life) compared with conventional medical management. |
| 1.3 | Spinal cord stimulation should be provided only after an assessment by a multidisciplinary team skilled in chronic pain assessment and management. |
| 1.4 | For the purposes of this guidance, a trial is defined as successful if the person can tolerate the spinal cord stimulation device and stimulation sensation, and their pain is relieved (a minimum of 80% of painful areas covered and a minimum of 50% pain relief achieved in that area). |
| 1.5 | When assessing the severity of pain and the trial of spinal cord stimulation, the multidisciplinary team should be aware of the need to ensure equality of access to the treatment. Tests to assess a trial of spinal cord stimulation should take into account a person's disabilities (such as physical impairments), or linguistic or other communication difficulties, and may need to be adapted. |
| 1.6 | If different spinal cord stimulation systems are considered to be equally suitable for a person, the least costly should be used. Assessment of cost should take into account acquisition costs for the lifetime of the device, including anticipated neurostimulator longevity, the stimulation requirements of the person with chronic pain and the support package offered. |
| 2 | Clinical need and practice |
| 2.1 | Chronic pain is pain that persists for more than 3 months or beyond the normal course of a disease or expected time of healing. This pain becomes a significant medical condition in itself rather than being a symptom. Chronic pain can affect people of all ages, although in general, its prevalence increases with age. Estimates of the prevalence of this condition in the UK vary from less than 10% to greater than 30% depending on the definition of chronic pain used. Chronic pain is accompanied by physiological and psychological changes such as sleep disturbances, irritability, medication dependence and frequent absence from work. Emotional withdrawal and depression are also common, which can strain family and social interactions. |
| 2.2 | Neuropathic pain is initiated or caused by nervous system damage or dysfunction. Neuropathic pain is difficult to manage because affected people often have a complex history with unclear or diverse aetiologies and comorbidities. Neuropathic conditions include failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS). People with FBSS continue to have back and/or leg pain despite anatomically successful lumbar spine surgery. It is not easy to identify a specific cause of neuropathic pain and people with FBSS may experience mixed back and leg pain. CRPS may happen after a harmful event or period of immobilisation (type I) or nerve injury (type II). Pain and increased sensitivity to pain are the most significant symptoms and are present in almost all people with CRPS. Other symptoms can include perceived temperature changes, weakness of movement and changes in skin appearance and condition. |
| 2.3 | Ischaemic pain is caused by a reduction in oxygen delivery to the tissues, usually caused by reduction in blood flow because of constriction of a vessel (vasospasm) or its obstruction by atheroma or embolus. Ischaemic pain is commonly felt in the legs or as angina, but can occur anywhere in the body. Ischaemic pain conditions include critical limb ischaemia (CLI) and refractory angina (RA). CLI is characterised by a reduction of blood flow to the legs. Poor oxygenation and biochemical or autonomic nerve responses can lead to gangrene, an increased risk of limb loss and a marked increase in mortality. CLI is also characterised by rest pain (which may be felt as a burning sensation), non-healing wounds and/or tissue necrosis. RA is defined as the occurrence of frequent angina attacks that are not controlled by optimal drug and/or revascularisation therapy, with the presence of coronary artery disease, making percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery unsuitable. |
| 2.4 | The goal of treatment for chronic pain is to make pain tolerable and to improve functionality and quality of life. It may be possible to treat the cause of the pain, but usually the pain pathways are modulated by a multidisciplinary pain management programme described as conventional medical management (CMM). This may include pharmacological interventions such as non-steroidal anti-inflammatory drugs, tricyclic antidepressants, anticonvulsants, analgesics and opioids. Non-pharmacological interventions, such as physiotherapy, acupuncture, transcutaneous electrical nerve stimulation and psychological therapies, can also be a part of CMM. For some chronic pain conditions there may also be condition-specific treatments; for example, people with FBSS may have a repeat operation. People with chronic pain may continue to experience pain despite CMM, and complete relief is rarely achieved. |
| 3 | The technologies |
| 3.1 |
Spinal cord stimulation (SCS) is a treatment for chronic pain that is usually considered after standard treatments (such as those listed in section 2.4) have failed. SCS modifies the perception of neuropathic and ischaemic pain by stimulating the dorsal column of the spinal cord. SCS is minimally invasive and reversible. A typical SCS system has four components:
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| 3.2 | Neurostimulators may be either implantable pulse generators ([IPGs] which use either a non-rechargeable or a rechargeable internal battery) or radio frequency devices (which receive energy in the form of radio frequency pulses from an external device powered by a rechargeable battery). Devices are not specific to pain conditions. However, SCS systems will have different longevities dependant on a person's pain patterns, stimulation power required and body area involved. Therefore the choice of SCS system will depend on these factors as well as preferences of the individual person's the clinician's preference. |
| 3.3 | Fourteen SCS devices manufactured by three companies have received European approval to market (CE marking) and are available in the UK. No publicly available UK list prices for SCS systems are available, but the Association of British Healthcare Industries (ABHI) provided indicative SCS equipment costs: a mid-range price based on the average cost of each of the manufacturer's best-selling product, a lower cost based on the average cost of each manufacturer's least expensive product, and an upper cost based on the average cost of the most expensive product. The prices supplied were: SCS system including neurostimulator, controller and charger, if applicable, but excluding leads £9282 (range £6858 to £13289); and leads £1544 (range £928 to £1804) or £1136 (range £1065 to £1158) for surgical or percutaneous implantation, respectively. Device and component prices may vary in different settings because of negotiated procurement discounts. |
| 3.4 | Advanced Bionics manufactures a rechargeable IPG (Precision SC-1110). The device is CE marked as an aid in the management of chronic intractable pain. |
| 3.5 | Advanced Neuromodulation Systems manufactures seven devices. Four are non-rechargeable IPGs (Genesis IPG 3608, Genesis XP 3609, Genesis XP Dual 3644 and Genesis G4), one is a rechargeable IPG (Eon), and two are radio frequency systems consisting of an implant with external rechargeable power (Renew 3408 and Renew 3416). The devices are CE marked as aids in the management of chronic intractable pain of the trunk and/or limbs. |
| 3.6 | Medtronic manufactures six devices. Four are non-rechargeable IPGs (Synergy, Synergy Versitrel, Itrel 3 and Prime ADVANCED) and two are rechargeable IPGs (Restore ADVANCED and Restore ULTRA). The devices are CE marked as aids in the management of chronic intractable pain of the trunk and/or limbs, peripheral vascular disease, or refractory angina pectoris. |
| 3.7 | Further details of contraindications, implant requirements and potential complications can be found in the implant manual for each SCS component. |
| 3.8 | For FBSS, the British Pain Society (BPS) suggests that SCS may be an alternative to a repeat operation or opioid use. For CRPS, the BPS suggests that SCS may be considered after pharmacotherapy and nerve blocks have been tried but have not provided adequate pain relief. It is acknowledged that SCS is not suitable for everyone with chronic pain, and that it should be used only as part of a pain management programme with other therapies and a strategy for rehabilitation. Re-intervention may be necessary to replace the SCS device because of complications (component failures, lead position or implant-related adverse events such as infection) or when the power source is depleted. |
| 3.9 | People selected for SCS normally have a stimulation trial to determine suitability for permanent implantation of a neurostimulator. This involves implantating the electrode(s) and leads with a temporary external device, which is used to mimic the effects of an implanted neurostimulator. A stimulation trial will assess tolerability (for example, of the stimulation sensation or the stimulation device) and the degree of pain relief likely to be achieved with full implantation. |
| 4 | Evidence and interpretation |
| The Appraisal Committee (appendix A) considered evidence from a number of sources (appendix B). | |
| 4.1 | Clinical effectiveness |
| 4.1.1 | The Assessment Group included 11 randomised controlled trials (RCTs) in their systematic review of clinical effectiveness. Three of these trials included people with neuropathic pain and eight trials included people with ischaemic pain. The devices used in all the trials were non-rechargeable IPG SCS systems produced by Medtronic. |
| Neuropathic pain conditions | |
| 4.1.2 | Two RCTs investigated the effect of SCS on the treatment of FBSS. One trial (PROCESS) compared SCS in combination with CMM with CMM alone. The other trial compared SCS in combination with CMM with repeat operation in combination with CMM. Follow-up in the PROCESS trial was at 6 and 12 months, and in the other trial at 6 months and after a mean of 2.9 years. The primary outcome in both studies was the proportion of people who had 50% or greater pain relief. |
| 4.1.3 | The PROCESS trial reported that SCS had a greater effect than CMM in terms of the proportion of people experiencing 50% pain relief at 6 months (48% and 9% in the SCS and CMM groups, respectively, p < 0.001) and 12 months (34% and 7% in the SCS and CMM groups, respectively, p = 0.005). The other trial also reported a statistically significant benefit in terms of those experiencing 50% pain relief, favouring SCS in comparison with repeat operation (39% and 12% in the SCS and repeat operation groups, respectively, p = 0.04). In the PROCESS trial, opioid use did not differ significantly between the two groups (56% and 70% using opioids in the SCS and CMM groups, respectively, p = 0.20). However, the other trial reported that SCS resulted in a significantly greater number of people reducing or maintaining the same dose of opioids when compared with repeat operation (87% and 58% in the SCS and repeat operation groups, respectively, p = 0.025). In the PROCESS trial the SCS group showed a significantly greater improvement in function compared with the CMM group for mean change in functional ability as measured by the Oswestry Disability Index. The other trial reported no statistically significant differences between SCS and repeat operation for pain related to daily activities or neurological function. The PROCESS trial measured health-related quality of life (HRQoL) using the Short Form-36 (SF-36) and reported statistically significant benefits favouring SCS across all domains of the SF-36, except for role-physical'. |
| 4.1.4 | One RCT investigated the effect of SCS in combination with physical therapy compared with physical therapy alone for the treatment of type I CRPS. The people in this trial were followed up at 6, 24 and 60 months. The primary outcome was change in pain intensity from baseline. |
| 4.1.5 | This trial reported that SCS in combination with physical therapy was more effective than physical therapy alone in reducing pain, measured as mean change on a visual analogue scale at 6 months (-2.4 cm and 0.2 cm, respectively, p < 0.001) and at 2 years (-2.1 cm and 0 cm, respectively, p = 0.001), but not at 5 years (-1.7 cm and -1.0 cm, respectively, p = 0.25). No statistically significant differences were identified between the SCS and physical therapy groups for improvement in time taken to perform tasks using the affected hand or foot. There were also no statistically significant differences for HRQoL at 6 months (percentage change in HRQoL: 6% in the SCS group and 3% in the physical therapy group) or 2 years (7% in the SCS group and 12% in the physical therapy group). |
| Ischaemic pain conditions | |
| 4.1.6 | Four RCTs investigated the effect of SCS for the treatment of CLI. Of these, two trials compared SCS in combination with CMM with CMM alone, one trial compared SCS in combination with oral analgesics with oral analgesics alone, and the fourth trial compared SCS in combination with prostaglandin E1 and standard wound care with prostaglandin E1 and standard wound care alone. In one trial the follow-up was at 6, 12, 18 and 24 months. In the other three trials there was a single follow-up at least 12 months after SCS. The primary outcome for all four trials was rate of limb salvage. One trial also included pain relief as a co-primary outcome. |
| 4.1.7 | Two of the trials reported pain relief outcomes; neither reported statistically significant differences between the intervention and control groups. One trial reported a mean reduction on a visual analogue scale of 2.45 cm for the SCS group and 2.61 cm for the CMM group at 18 months. The same trial reported medication outcomes: SCS was more effective than CMM in reducing use of analgesics at 6 months (p = 0.002), but not at 18 months (p = 0.70). |
| 4.1.8 | All four trials reported limb survival or amputation rates, but none reported statistically significant differences between groups. At 24 months, one trial reported 52% limb survival in the SCS group and 46% in the CMM group (p = 0.47). Another trial reported six major amputations in the SCS group and nine major amputations in the CMM group at 24 months. In one trial at 12 months, 16% of people in the SCS group had undergone a major amputation compared with 20% in the prostaglandin E1 group. One trial reported a borderline statistically significantly lower amputation rate for SCS compared with analgesics when categorising amputations by 'none', 'moderate' or 'major'.(p = 0.05). One trial reported the results for a subgroup of people with intermediate skin microcirculation before treatment. In this subgroup, there was a non-significant trend towards lower amputation rate in the SCS group at 18 months follow-up. One trial assessed HRQoL. There was no statistically significant difference between the SCS and CMM groups (mean score on the Nottingham Health Profile at 18 months was 35 in the SCS group and 34 in the CMM group). |
| 4.1.9 | Four RCTs investigated the effect of SCS for the treatment of angina. One trial compared SCS with no SCS device implanted, one trial compared SCS with an implanted but inactive SCS system, one trial compared SCS with CABG, and one trial compared SCS with percutaneous myocardial revascularisation. All four trials recruited people with RA for whom revascularisation procedures were unsuitable or for whom it was considered that revascularisation would not improve prognosis. The follow-up was approximately 6 weeks in two trials and 1 year or more in the other two trials. In three trials, the primary outcome was exercise capacity. In one trial, the primary outcome was frequency of angina attacks. |
| 4.1.10 | One trial reported pain outcomes. This trial reported no statistically significant difference between SCS and inactive stimulator in terms of pain relief (measured as mean reduction in VAS: 1.1 cm versus 0.2 cm, respectively). Three trials measured nitrate consumption. Two of these trials reported statistically significant benefits favouring SCS over no SCS device (median weekly nitrate consumption 1.6 and 8.5, respectively, p < 0.05) or an inactive SCS device (change in nitrate consumption -48% and 27%, respectively, p = 0.03). One of the trials found no statistically significant difference between SCS and CABG for short-acting nitrates but a statistically significant difference favouring CABG over SCS for long-acting nitrates (p < 0.0001). |
| 4.1.11 | Three trials reported frequency of angina attacks. Two of these reported a statistically significant difference favouring SCS when compared with no SCS (median number of angina attacks a week: 9.0 and 13.6, respectively) or inactive SCS (number of angina attacks a day: 2.3 and 3.2, respectively). One trial reported no statistically significant difference between SCS and CABG for mean number of angina attacks a week (4.4 and 5.2, respectively). |
| 4.1.12 | All four trials reported functional outcomes such as exercise duration or workload capacity. Two studies reported a statistically significant difference favouring the use of SCS when compared with inactive SCS (mean exercise duration in seconds: 533 and 427, respectively) and no SCS (exercise duration in seconds: 827 and 694, respectively). Another trial reported no statistically significant difference between the SCS and percutaneous myocardial revascularisation groups for exercise duration (mean exercise duration in minutes: 7.08 and 7.12, respectively, p = 0.466). |
| 4.1.13 | All four trials reported HRQoL outcomes. One trial reported that HRQoL (daily and social activity scores) was more improved by SCS than no SCS at 6-8 weeks (p < 0.05). The other three trials did not identify any statistically significant differences in HRQoL outcomes. |
| 4.2 | Cost effectiveness |
| 4.2.1 | A joint submission was received from Advanced Bionics Advanced Neuromodulation Systems and Medtronic, under the auspices of the ABHI, including an economic evaluation. The Assessment Group also developed their own economic evaluation. Both the ABHI and Assessment Group models used a similar structure. |
| The manufacturer's submission | |
| 4.2.2 | The ABHI submission evaluated the cost effectiveness of SCS for the treatment of neuropathic pain and modelled both FBSS (SCS with CMM compared with either CMM alone or repeat operation in combination CMM) and CRPS (SCS with CMM compared with CMM alone). Ischaemic pain conditions were not modelled. The model included two-stages: a decision tree for short-term treatment with SCS (first 6 months), followed by a Markov process for SCS treatment from 6 months to 15 years. Probabilities of events were based on data from the RCTs of FBSS and CRPS. The time frame in the second stage of the model was based on an observational study that investigated clinical predictors of outcomes for people using SCS systems over a 15-year period. T reatment success was defined as 50% or greater reduction in pain. |
| 4.2.3 | Health-state utilities were based on the EQ-5D. Utility values were assumed to be the same for both FBSS and CRPS, and were based on the FBSS PROCESS trial. The baseline utility value for all patients was 0.168 (no pain reduction). Other stages were valued at optimal pain relief (0.598), optimal pain relief and complications (0.528), suboptimal pain relief (0.258), and suboptimal pain relief and complications (0.258). |
| 4.2.4 | Costs associated with FBSS and CRPS were taken from the PROCESS trial. In the base case, the cost of an SCS device was £9282. This cost was described in the submission as the average cost of the best-selling device from each manufacturer. In the base case, device longevity was set to 4 years, after which the neurostimulator was replaced. |
| 4.2.5 | For FBSS, the model produced an incremental cost-effectiveness ratio (ICER) of £9155 per quality-adjusted life year (QALY) gained when SCS in combination with CMM was compared with CMM alone. A comparison of SCS and CMM with repeat operation in combination CMM produced an ICER of £7954 per QALY gained. For CRPS, the model produced an ICER of £18,881 per QALY gained compared with CMM. Sensitivity analyses demonstrated that the model was sensitive to assumptions about device longevity and device cost. |
| Assessment Group's economic evaluation of neuropathic pain | |
| 4.2.6 | The Assessment Group developed a two-stage model, comprising a decision tree to 6 months with a Markov process extending to 15 years. Both FBSS and CRPS conditions were modelled using data from the two trials of FBSS and the trial of CRPS. For FBSS, SCS in combination with CMM was compared in the model with CMM alone, and with repeat operation in combination with CMM (the latter is referred to in the remainder of the document as 'repeat operation'). For CRPS, SCS in combination with CMM was compared with CMM alone. Patients entered into the second stage of the model in the same health state that they were assigned to at the end of the first 6 months (in the first stage of the model). The time frame was based on an observational study that investigated clinical predictors of outcomes for people using SCS systems over a 15-year period. |
| 4.2.7 | The effect of SCS was assumed to continue over the time horizon of the model except for an annual withdrawal rate from SCS of 3.24% per annum, assumed to be because of gradual loss of pain control. This figure was from a longitudinal observational study. Complications (after 6 months) were assumed to be at a rate of 18% per annum and no complications were assumed to occur in the CMM only groups. In the base case, device longevity was set to 4 years and explored in sensitivity analyses. |
| 4.2.8 | The Assessment Group used cost data from a range of published sources including the 'British national formulary' (BNF), the Personal Social Services Research Unit (PSSRU) and published studies. In the Assessment Group base case, the combined cost of a neurostimulator and control system was lower than that used in the ABHI submission. This cost reflected a mid-range of device prices obtained, commercial in confidence, in a survey of manufacturers conducted by the Assessment Group. The Assessment Group also provided sensitivity analyses for a broad range of devices costs ranging from £5000 - £15,000. The Assessment Group base case results are not described in this document. Instead Assessment Group sensitivity analyses using a device cost of £9000 are presented, which is similar to the £9282 presented in the ABHI submission. |
| 4.2.9 | Health-state utilities were based on the EQ-5D and, in contrast to the ABHI model, differed between FBSS and CRPS. Utility data were obtained from the PROCESS trial for FBSS and a cross-sectional survey that investigated the burden of neuropathic pain for a range of conditions, including CRPS. In the model, the baseline utility value for FBSS for all patients was 0.168 (no pain reduction). Other stages were valued at optimal pain relief (0.598), optimal pain relief and complications (0.528), suboptimal pain relief (0.258), and suboptimal pain relief and complications (0.258). For CRPS, the baseline utility value for all patients was 0.16 (no pain reduction). Other stages were valued at optimal pain relief (0.67), optimal pain relief and complications (0.62), suboptimal pain relief (0.46), and suboptimal pain relief and complications (0.41). |
| 4.2.10 | For FBSS, the incremental cost effectiveness ratio (ICER) for SCS in combination with CMM, when assuming device longevity of 4 years and using a device price figure of £9000, were £10,480 per QALY gained compared with CMM alone and £9219 per QALY gained compared with repeat operation. |
| 4.2.11 | Results were sensitive to device longevity and price. At a device price of £9000, the ICERs for SCS in combination with CMM were less than £20,000 per QALY gained for device longevity of 3 or more years, compared with CMM alone or with repeat operation. At device longevity of 4 years, the ICERs for SCS in combination with CMM were less than £20,000 per QALY gained for a device price less than £13,000 compared with CMM alone, and £15,000 or less compared with repeat operation. |
| 4.2.12 | For CRPS, the ICERs for SCS in combination with CMM compared with CMM alone, when assuming device longevity of 4 years and using a device price of £9000, produced an ICER of £32,282 per QALY gained. |
| 4.2.13 | Results were sensitive to device longevity and cost. At a device price of £9000 the ICERs for SCS in combination with CMM compared with CMM alone were less than £20,000 per QALY gained for device longevity of 5 years or longer. At longevity of 4 years, the ICERs were less than £30,000 per QALY gained for device prices up to £8000, and less than £20,000 per QALY gained for device prices up to £6000. |
| Assessment Group's economic evaluation ofi schaemic pain | |
| 4.2.14 | The Assessment Group did not carry out an economic analysis of CLI, but explored the cost effectiveness of SCS for the treatment of RA using an alternative modelling approach. A threshold analysis was presented based on a mathematical model that incorporated data from a prospective observational study. This study compared the outcomes for CABG, PCI and CMM in groups of people for whom treatment with CABG, PCI or both (CABG and PCI) would be appropriate. Data for costs were taken from the BNF, the PSSRU and a study of outcomes in people who underwent revascularisation using CABG, PCI or both. Utility data were also identified in this study, which were reported after 6 years of follow-up. The time horizon of the model was 6 years. |
| 4.2.15 | The threshold analysis was presented as additional QALYs that would be needed for SCS to be cost effective at different levels of willingness to pay. In these analyses, it was assumed that survival in the SCS and comparator groups (CABG, PCI and CMM) was similar. The average minimum utility required for SCS to be cost effective at £20,000 and £30,000 per QALY gained, assuming similar survival, was then calculated. For each comparator (CABG, PCI and CMM), three scenarios were modelled based on groups of people for whom CABG, PCI or either revascularisation procedures would be clinically appropriate. |
| 4.2.16 |
Results of the analysis indicated that for people who are suitable for treatment with:
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| 4.3 | Consideration of the evidence |
| 4.3.1 | The Appraisal Committee reviewed the data available on the clinical and cost effectiveness of SCS for the treatment of chronic pain, having considered evidence on the nature of the condition and the value placed on the benefits of SCS by people with chronic pain, those who represent them, and clinical specialists. It was also mindful of the need to take account of the effective use of NHS resources. |
| 4.3.2 | The Committee considered the pathways of care for people with chronic pain and the potential place of SCS in such pathways. The Committee heard from clinical specialists and the patient expert about patient referral and access to specialist pain services and patient experiences with SCS. In addition, the Committee heard about the use of SCS in UK clinical practice, including the application of BPS guidelines. It heard that BPS guidelines provided a general guide to the pathway of care, but that people had to be managed flexibly depending on their condition. The Committee appreciated that to ensure a flexible approach and individualisation of treatments that people with chronic pain conditions should be managed using a multidisciplinary approach, with consideration given to a range of treatments as part of their care. In addition, these treatments may vary for different chronic pain conditions because of their different presentation and management. The Committee concluded that it was necessary for people with chronic pain conditions to be managed by a multidisciplinary team. Furthermore, the Committee noted that pain measuring at least 50 mm on a 0-100 mm visual analogue scale was an inclusion criterion in the clinical trials of SCS in neuropathic pain. It therefore concluded that people considered for treatment with SCS should be assessed as experiencing a similar severity of pain. |
| 4.3.3 | The Committee discussed the use of a trial of stimulation before the permanent implantation of an SCS device, such as the achievement of pain relief (a minimum of 80% the person's painful areas covered and a minimum of 50% pain relief achieved in that area) as was carried out in the clinical trial considered in the evidence presented. The Committee heard from the clinical specialists that a trial of stimulation was normally, but not always, used before permanent implantation. The Committee heard that there could be benefits from a trial of stimulation, because it could help to identify people who would benefit from the complete procedure and gave people the opportunity to experience what stimulation was like. However, the Committee heard that trial stimulations may be associated with increased costs because of the need for additional hospital attendances and also a possible increase in the risk of adverse effects such as infection. On balance, the Committee concluded that because the key trials and the economic modelling included a trial of stimulation, it was appropriate to recommend the use of permanent implantation of SCS devices only after a successful trial and that the criteria for a successful trial should follow those applied in the available studies. |
| 4.3.4 | The Committee noted that the criteria for the assessment of severity of pain and a successful trial of stimulation may not be appropriate for people with physical or sensory disabilities or for people with other linguistic or cognitive difficulties. The Committee concluded that healthcare professionals assessing the outcomes of a trial of stimulation should take these factors into account. In these situations, modification of the testing procedure or alternative tests may be required. |
| 4.3.5 | The Committee noted that there were a range of SCS systems available at different prices. The Committee heard from clinical specialists that one of the factors affecting the choice of device was the complexity of pain pattern and the extent of pain. For example, a person with a single painful limb may be expected to derive greater longevity from the same device than someone with a more complex pain pattern or greater body area affected. Clinical specialists suggested that device longevity may exceed 4 years, even with a non-rechargeable device. The Committee therefore recognised that price and longevity were not independent and that longevity varies depending on an individual's pain characteristics. |
| 4.3.6 | The Committee examined the clinical-effectiveness evidence for SCS. The Committee noted that only a small number of clinical trials had been identified and that relatively small numbers of people were included in these studies. The Committee heard from clinical specialists that there was additional evidence on the use of SCS in larger numbers of people than in the included trials, but this was from non-controlled studies and clinical experience. The Committee noted that the trials were limited to four chronic pain conditions: FBSS, CRPS, CLI and RA. The Committee was aware, however, that neuropathic and ischaemic pain included a much larger group of pain conditions. The Committee heard from clinical specialists that, in their view, the different pain conditions did not need to be considered separately for the use of SCS. However, the Committee concluded that guidance on the use of SCS should relate specifically to those chronic pain conditions for which there was supportive clinical trial evidence. |
| 4.3.7 | The Committee examined the evidence on the clinical effects of SCS in the treatment of FBSS and CRPS. The Committee agreed that for both conditions the evidence suggested that SCS was effective in reducing pain. However, the Committee noted that for CRPS this difference was not sustained at the 5-year follow-up. The Committee heard from clinical specialists that this may have been partly explained by crossover between the treatment arms of the trial, but they agreed that there was likely to be a reduction in pain control over time. However, the clinical specialists also said that they would expect this waning of effect to occur for people receiving CMM as well. The Committee concluded that there was considerable uncertainty about how the effects of SCS were sustained over time. |
| 4.3.8 | The Committee next considered the clinical-effectiveness evidence for CLI and RA. It was aware that the primary outcomes in these studies were functional rather than pain relief, and noted that no studies had demonstrated statistically significant differences for pain outcomes. The Committee considered that there was some evidence of lower rates of angina and reduced medication use from studies of RA. In addition, the Committee heard that for CLI there may be greater benefits from SCS for certain subgroups of people with an increase in transcutaneous oxygen tension after stimulation is started. However, the Committee heard from clinical specialists that the benefits of SCS for CLI and RA were less certain than for FBSS and CRPS. The Committee concluded that there was considerable uncertainty about the benefits of SCS in people with CLI and RA. |
| 4.3.9 | The Committee examined the economic modelling that had been carried out for the appraisal. It noted that both the model by the Assessment Group and that submitted by the ABHI had a similar structure. However, the Committee was aware that the models differed in cost data and, for CRPS, utility data used. The Committee agreed that it was appropriate to consider the outputs from both models as well as sensitivity analyses produced by the Assessment Group. The Committee noted that both models assumed that the benefit from SCS was stable over 15 years. The Committee considered that the trial data indicated that this assumption may not be appropriate and could be overly optimistic given the testimony of the clinical experts. The Committee concluded that there could be a loss of benefit over time and that this would mean that the ICERs generated by the modelling were underestimated. In addition, the Committee noted that rare, but potentially serious, complications were not included in the model. The Committee therefore concluded that both models may underestimate the ICERs for SCS in the treatment of chronic pain. |
| 4.3.10 | The Committee considered the estimates of cost effectiveness for FBSS. The Committee noted that the ABHI and Assessment Group models produced similar estimates of the ICERs for the use of SCS compared with alternative treatments, and that these were less than £11,000 per QALY gained for the base-case analyses. Although aware of the possible underestimation of the ICER, the Committee was persuaded that the use of SCS for the treatment of FBSS would be a cost-effective use of NHS resources. |
| 4.3.11 | The Committee examined the estimates of cost effectiveness for CRPS. It noted that the use of an alternative source of utility data in the models developed by ABHI and the Assessment Group had led to different ICERs. The ABHI estimated an ICER of £18,881 when using a £9282 device price, whereas the Assessment Group estimated an ICER of £32,282 per QALY gained when using the £9000 device price. The Committee noted that the models used different sources of utility data and that neither captured the utility of a person with CRPS accurately, as one source was a trial of FBSS and the other a wider survey of neuropathic pain conditions. The Committee was aware that device longevity in CRPS may exceed 4 years and that device price and longevity could affect the ICER. Taking into consideration the range of ICERs and the concerns about the extrapolation of benefits, the Committee was not persuaded that the use of SCS for the treatment of CRPS could currently be recommended for routine care as a cost-effective use of NHS resources. However, the Committee acknowledged that further research could reduce the uncertainties in the evidence available. Therefore, the Committee considered that a recommendation for the use of SCS for the treatment of CRPS only in research was appropriate. |
| 4.3.12 | The Committee noted that the ABHI had not provided an economic evaluation of the use of SCS for ischaemic pain, and that the Assessment Group had only been able to complete exploratory threshold analyses for RA because of limited availability of evidence. The Committee also noted the additional information provided by the ABHI in response to the Assessment Group's threshold analysis. Examining the analyses for RA, the Committee considered that their relevance was limited as they were based on a population of people for whom treatment with CABG or PCI was suitable. However these techniques are often unsuitable for people with RA. The Committee concluded that there was insufficient evidence on survival and benefits in HRQoL in this population, as well as on cost effectiveness. It therefore concluded that the use of SCS for the treatment of CLI or RA could currently not be recommended. However, acknowledging the uncertainties in the evidence, the Committee recommended that use of SCS for the treatment of CLI and RA be subject to further research. |
| 4.3.13 | The Committee was aware that there was a range of SCS devices available. The Committee heard from clinical specialists that, in clinical practice, they took into account factors such as the pattern of pain and the amount and intensity of stimulation required. The clinical specialists stated that for people with complex pain patterns, complex devices may be more appropriate as they could provide a more complete response to the pain and have a greater longevity, meaning that re-intervention is required less often. The Committee considered that rechargeable devices, although more costly than some non-rechargeable neurostimulators, may have greater longevity and that this may be particularly important for those people requiring high intensity and/or broad coverage of stimulation. However, the Committee concluded that if, after consultation between the responsible clinician and the patient, it was considered that more than one SCS system was likely to be equally appropriate, the least costly should be used. The Committee considered that assessment of cost should take into account acquisition costs for the lifetime of the device, including anticipated neurostimulator longevity, the stimulation and coverage requirements of the person with chronic pain and the support package offered. |
| 5 | Implementation |
| 5.1 | The Healthcare Commission assesses the performance of NHS organisations in meeting core and developmental standards set by the Department of Health in 'Standards for better health' issued in July 2004. The Secretary of State has directed that the NHS provides funding and resources for medicines and treatments that have been recommended by NICE technology appraisals normally within 3 months from the date that NICE publishes the guidance. Core standard C5 states that healthcare organisations should ensure they conform to NICE technology appraisals. |
| 5.2 | Healthcare standards for Wales' was issued by the Welsh Assembly Government in May 2005 and provides a framework both for self-assessment by healthcare organisations and for external review and investigation by Healthcare Inspectorate Wales. Standard 12a requires healthcare organisations to ensure that patients and service users are provided with effective treatment and care that conforms to NICE technology appraisal guidance. The Assembly Minister for Health and Social Services issued a Direction in October 2003 that requires local health boards and NHS trusts to make funding available to enable the implementation of NICE technology appraisal guidance, normally within 3 months. |
| 5.3 |
NICE has developed tools to help organisations implement this guidance (listed below). These are available on our website (www.nice.org.uk/TAXXX). [NICE to amend list as needed at time of publication]
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| 6 | Proposed recommendations for further research |
| 6.1 | The Committee recommended that further comparative studies (preferably in the form of randomised controlled trials) should be conducted. These studies should be designed to generate robust evidence about the durability of the benefits of spinal cord stimulation (including pain relief and quality of life) compared with conventional medical management. |
| 7 | Related NICE guidance |
| Under development | |
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NICE is developing the following guidance (details available from www.nice.org.uk):
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| 8 | Proposed date for review of guidance |
| 8.1 | The review date for a technology appraisal refers to the month and year in which the Guidance Executive will consider whether the technology should be reviewed. This decision will be taken in the light of information gathered by the Institute, and in consultation with consultees and commentators. |
| 8.2 | It is proposed that the guidance on this technology is considered for review in November 2011. The Institute would particularly welcome comment on this proposed date. |
| David Barnett |
| Chair, Appraisal Committee |
| June 2008 |
| Appendix A. Appraisal Committee members and NICE project team | |
| A | Appraisal Committee members |
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The Appraisal Committee is a standing advisory committee of the Institute. Its members are appointed for a 3-year term. A list of the Committee members who took part in the discussions for this appraisal appears below. The Appraisal Committee meets three times a month except in December, when there are no meetings. The Committee membership is split into three branches, each with a chair and vice-chair. Each branch considers its own list of technologies and ongoing topics are not moved between the branches. Committee members are asked to declare any interests in the technology to be appraised. If it is considered there is a conflict of interest, the member is excluded from participating further in that appraisal. The minutes of each Appraisal Committee meeting, which include the names of the members who attended and their declarations of interests, are posted on the NICE website. |
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| Dr Jane Adam | |
| Radiologist, St George's Hospital, London | |
| Professor A E Ades | |
| Professor of Public Health Science, Department of Community Based Medicine, University of Bristol | |
| Dr Amanda Adler | |
| Consultant Physician, Cambridge University Hospitals Trust | |
| Dr Tom Aslan | |
| General Practitioner, The Hampstead Group Practice, London | |
| Professor David Barnett (Chair) | |
| Professor of Clinical Pharmacology, Leicester Royal Infirmary | |
| Mrs Elizabeth Brain | |
| Lay Member | |
| Dr Karl Claxton | |
| Professor of Health Economics, Department of Economics & Related Research, The University of York | |
| Simon Dixon | |
| Reader in Health Economics, University of Sheffield | |
| Mrs Fiona Duncan | |
| Clinical Nurse Specialist, Anaesthetic Department, Blackpool Victoria Hospital, Blackpool | |
| Professor Christopher Eccleston | |
| Director Centre for Pain Research, University of Bath | |
| Dr Paul Ewings | |
| Statistician, Taunton & Somerset NHS Trust, Taunton | |
| Mr John Goulston | |
| Chief Executive, Barking, Havering and Redbridge Hospitals NHS Trust | |
| Mr Adrian Griffin | |
| VP Strategic Affairs, LifeScan, Johnson & Johnson | |
| Professor Philip Home (Vice Chair) | |
| Professor of Diabetes Medicine, Newcastle University | |
| Dr Ann Richardson | |
| Lay Member | |
| Mr Mike Spencer | |
| General Manager, Facilities and Clinical Support Services, Cardiff and Vale NHS Trust | |
| Dr Simon Thomas | |
| Consultant Physician and Reader in Therapeutics, Newcastle Hospitals NHS Foundation Trust and Newcastle University | |
| Mr David Thomson | |
| Lay Member | |
| Dr Paul Watson | |
| Director of Commissioning, East of England Strategic Health Authority | |
| Mr Cliff Snelling | |
| Lay member | |
| Mrs Eleanor Grey | |
| Lay Member | |
| B | NICE project team |
| Each technology appraisal is assigned to a team consisting of one or more health technology analysts (who act as technical leads for the appraisal), a technical adviser and a project manager. | |
| Ruaraidh Hill | |
| Technical Lead | |
| Zoe Garrett | |
| Technical Adviser | |
| Eloise Saile | |
| Project Manager | |
| Appendix B. Sources of evidence considered by theCommittee | |
| A |
The assessment report for this appraisal was prepared by The University of Sheffield, School of Health and Related Research (ScHARR).
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| B | The following organisations accepted the invitation to participate in this appraisal. They were invited to comment on the draft scope, assessment report and the appraisal consultation document (ACD). Organisations listed in I and II were also invited to make written submissions and have the opportunity to appeal against the final appraisal determination. |
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I Manufacturer/sponsor:
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II Professional/specialist and patient/carer groups:
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III Other consultees
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IV Commentator organisations (did not provide written evidence and without the right of appeal)
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| C |
The following individuals were selected from clinical specialist and patient advocate nominations from the non-manufacturer/sponsor consultees and commentators. They participated in the Appraisal Committee discussions and provided evidence to inform the Appraisal Committee's deliberations. They gave their expert personal view on s pinal cord stimulation for chronic pain of neuropathic or ischaemic origin by attending the initial Committee discussion and/or providing written evidence to the Committee. They are invited to comment on the ACD.
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This page was last updated: 30 March 2010