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| Quality of life, resource consumption and costs of spinal cord stimulation versus conventional medical management in neuropathic pain patients with failed back surgery syndrome (PROCESS trial) |
| Manca A, Kumar K, Taylor R S, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, Taylor R J, Goeree R, Sculpher M J |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. CRD summary This study investigated the first six months of costs and quality of life outcomes, for the treatment of patients experiencing neuropathic pain and failed back surgery syndrome, using spinal cord stimulation (SCS) compared with conventional medical management (CMM) alone. The authors concluded that SCS had higher costs to the health system, but also yielded important improvements in health-related quality of life. The study methods were transparent, thorough and appropriate, and the authors’ conclusions reflect the analysis undertaken. Type of economic evaluation Cost-effectiveness analysis Study objective This study estimated the costs and health effects of spinal cord stimulation (SCS) for the treatment of neuropathic pain in patients with failed back surgery syndrome. These patients were 18 years or older, suffering from neuropathic radial pain, in the legs, with or without associated back pain, and had a history of nerve injury. Interventions SCS with conventional medical management (CMM) was compared with CMM alone. SCS began with a screening trial to identify those patients who experienced at least 80% overlap of their pain with stimulation-induced paraesthesia and at least 50% leg pain relief. These patients received an implantable pulse generator (IPG), while the CMM group received oral medications, such as opioids, non-steroidal anti-inflammatory drugs, and anti-depressants. Location/setting Europe, Canada, Australia and Israel/out-patient care (12 centres). Methods Analytical approach:This evaluation was based on the first six months of data from a single clinical trial (Kumar, et al. 2005, see ‘Other Publications of Related Interest’ below for bibliographic details). The authors did not explicitly state the study perspective.
Effectiveness data:The effectiveness data for health-related quality of life were derived from a single, prospective, randomised clinical study (Kumar, et al. 2005). The Short Form (SF)-36 was used for assessment at baseline, three, and six months, with 100 participants completing the questionnaires. An intention-to-treat analysis was undertaken, and a cross-over design allowed three patients to switch to SCS and receive an IPG after the six-month trial period. Ordinary least-squares regression and analysis of covariance statistics were used to estimate the differential change in EuroQol-5D (EQ-5D) scores in the two groups over time.
Monetary benefit and utility valuations:The utility scores were measured with the EQ-5D at baseline, three, and six months with 100 participants completing the questionnaires.
Measure of benefit:The measure of benefit was health-related quality of life.
Cost data:The resource types for the cost analyses were collected on case report forms and included: pre-implant screening and IPG implant, medications, non-drug therapy (e.g., massage, physiotherapy, acupuncture) and resources related to complications such as additional surgery, hospitalisations for adverse events, and medical tests. As most of the participants were located in the UK and Canada, the unit costs were obtained from a combination of national cost reports and published literature and applied to resource quantities separately for the UK and Canada. Regression-based methods were used to analyse the cost data (Hoch, et al. 2002, see ‘Other Publications of Related Interest’ below for bibliographic details). All costs were reported in 2005 to 2006 UK pounds sterling (£), Canadian dollars (CAD), and Euros (EUR, at a conversion rate of CAD 1 = EUR 1.54) and inflationary adjustments were made using the health care price indices from the two countries.
Analysis of uncertainty:Not stated. Results The total average treatment cost with SCS over six months was £15,081 (CAD 19,486, EUR 12,653) compared with CMM which was £3,573 (CAD 3,994, EUR 2,594). The adjusted mean costs for health care resource utilisation for SCS were significantly higher than for CMM. The CMM group incurred a significantly higher proportion of non-SCS related costs (i.e., non-drug and drug pain treatments) than the SCS group at six months.
The incremental mean improvements from baseline in EQ-5D scores for SCS compared with CMM were 0.27 (95% confidence interval, CI: 0.15 to 0.39) at three months and 0.23 (95% CI: 0.12 to 0.35) at six months, after adjustment for baseline EQ-5D scores.
Cost-effectiveness ratios were not synthesised and the results were presented individually. Authors' conclusions The authors concluded that SCS incurred higher health system costs than CMM at six months, but also produced important gains in health-related quality of life. CRD commentary Interventions:The interventions were clearly reported and the comparator CMM alone group reflected the current clinical practice across the participating countries. You should decide if these interventions are relevant to your own setting.
Effectiveness/benefits:The effectiveness data were derived from a single multi-centre study and the selection of this study was justified by the authors. The measurement of quality of life involved the most widely-used and acceptable preference-based generic quality of life tool (EQ-5D). Quality of life analyses over time and between groups were clearly reported and rigorously analysed, taking into account participant heterogeneity.
Costs:The types of costs appeared appropriate for a health system perspective, although this perspective was implicit rather than stated. The sources of costs were clearly reported with all data sources presented. Limitations were acknowledged, by the authors, in terms of the short time frame and the omission of other longer-term costs relating to maintenance of SCS hardware and costs of other therapies. Between country cost comparisons were discussed, highlighting the variations in unit costs between the UK and Canada.
Analysis and results:The costs and effects were not combined into incremental cost-effectiveness ratios. However, the cost and quality of life analyses were transparent, thoroughly reported, and enable the reader to capture all the analytical steps taken. Any occurrences of missing data and losses to follow-up were not discussed by the authors and readers should refer to the key clinical data source for further details (Kumar, et al. 2005). Sensitivity analyses were not undertaken, but the statistical analyses conducted ensured that the results were robust and reliable. The authors indicated that a full cost-effectiveness study would be undertaken in the future, when longer-term data became available.
Concluding remarks:The study appears to have been well conducted and was explicitly and clearly reported. The authors’ conclusions appear to be accurate. Bibliographic details Manca A, Kumar K, Taylor R S, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, Taylor R J, Goeree R, Sculpher M J. Quality of life, resource consumption and costs of spinal cord stimulation versus conventional medical management in neuropathic pain patients with failed back surgery syndrome (PROCESS trial) European Journal of Pain 2008; 12(8): 1047-1058 Other publications of related interest Kumar K, North RB, Taylor RS, et al. Spinal cord stimulation versus conventional medical management: a prospective, randomized, controlled, multicenter study of patients with failed back surgery syndrome (PROCESS study). Neuromodulation 2005;8:213-8.
Hoch JS, Briggs AH, Willan A. Something old, something new, something borrowed, something BLUE: a framework for the marriage of health econometrics and cost-effectiveness analysis. Health Econ 2002;11:415-30. Indexing Status Subject indexing assigned by NLM MeSH Analgesics /economics /therapeutic use; Australia; Canada; Cost-Benefit Analysis; Electric Stimulation Therapy /economics /statistics & Europe; Female; Health Care Costs /statistics & Health Resources /economics /utilization; Health Status; Hospitalization /statistics & Humans; Israel; Longevity; Low Back Pain /economics /psychology /therapy; Male; Middle Aged; Neurosurgical Procedures /adverse effects; Patient Satisfaction /statistics & Peripheral Nervous System Diseases /economics /psychology /therapy; Postoperative Complications /economics /psychology /therapy; Prospective Studies; Quality of Life /psychology; Spinal Cord /physiology /surgery; Spinal Diseases /surgery; Spine /pathology /physiopathology /surgery; Syndrome; Treatment Failure; numerical data; numerical data; numerical data; numerical data /trends AccessionNumber 22008102173 Date bibliographic record published 07/04/2009 Date abstract record published 15/07/2009 |
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