WA Health Technology Assessment - HTA HEALTH TECHNOLOGY ASSESSMENT UPDATED HTA FINAL REPORT ELECTRICAL NERVE STIMULATION FOR THE TREATMENT OF PAIN UPDATED DATE: FRIDAY, NOVEMBER 13, 2009 Health Technology Assessment Program 676 Woodland Square Loop SE P.O. Box 42712 Olympia, WA 98504-2712 http://www.hta.hca.wa.gov Updated FINAL: ENS: 11-13-09 1 of 104 WA Health Technology Assessment - HTA ELECTRICAL NERVE STIMULATION FOR THE TREATMENT OF PAIN Provided by: Spectrum Research, Inc. Prepared by: Jocelyn M. Weiss, PhD, MPH Andrea C. Skelly, PhD, MPH Nora Henrikson, PhD, MPH Lisa Kercher, PhD, MPH Joseph R. Dettori, PhD, MPH With assistance from: Erika D. Ecker, BS This technology assessment report is based on research conducted by a contracted technology assessment center, with updates as contracted by the Washington State Health Care Authority. This report is an independent assessment of the technology question(s) described based on accepted methodological principles. The findings and conclusions contained herein are those of the investigators and authors who are responsible for the content. These findings and conclusions may not necessarily represent the views of the HCA/Agency and thus, no statement in this report shall be construed as an official position or policy of the HCA/Agency. The information in this assessment is intended to assist health care decision makers, clinicians, patients and policy makers in making sound evidence-based decisions that may improve the quality and cost- effectiveness of health care services. Information in this report is not a substitute for sound clinical judgment. Those making decisions regarding the provision of health care services should consider this report in a manner similar to any other medical reference, integrating the information with all other pertinent information to make decisions within the context of individual patient circumstances and resource availability. Updated FINAL: ENS: 11-13-09 2 of 104 WA Health Technology Assessment - HTA TABLE OF CONTENTS EXECUTIVE SUMMARY 7 RATIONALE FOR THE APPRAISAL 21 1. BACKGROUND 1.1 The Conditions: Acute and Chronic Pain 22 1.2 The Technology and its Comparators 22 1.3 Clinical Guidelines 25 1.4 Previous Health Technology Assessments 27 1.5 Medicare and Private Insurer Coverage Policies 28 1.6 WASHINGTON STATE DATA 31 2. THE EVIDENCE 2.1 Systematic Literature Review 32 2.2 Methods 33 2.3 Quality of Literature Available 37 2.4 Outcome Measures 41 3. RESULTS 3.1 Key Question 1: What is the evidence of efficacy and effectiveness of TENS for the treatment of acute and chronic pain? 44 3.2 Key Question 2: What is the evidence of about the safetly profile for TENS? 80 3.3 Key Question 3: Is there evidence of differential efficacy or safety issues with the use of TENS? What is the evidence of cost implications and cost effectiveness of TENS? 81 4. SUMMARY AND IMPLICATIONS 4.1 Summary with respect to efficacy and effectiveness of transcutaneous electrical nerve stimulation (TENS) in the treatment of acute and chronic pain 85 4.2 Summary with respect to the safety of TENS 89 4.3 Summary with respect to economic studies 90 BIBLIOGRAPHY 96 Updated FINAL: ENS: 11-13-09 3 of 104 WA Health Technology Assessment - HTA LIST OF TABLES Table 1. Overall Strength of Evidence (SoE) Criteria 13 Table 2. Summary of Evidence for each Key Question 1 14 Table 3. Summary of Evidence for each Key Question 2 19 Table 4. Summary of Evidence for each Key Question 3 20 Table 5. Overview of previous technology assessments of electrical nerve stimulation for pain management. 27 Table 6. Overview of payer technology assessments and policies for electrical nerve stimulation 29 Table 7. Inclusion and Exclusion Criteria for this Assessment 32 Table 8. Definition of the different levels of evidence for articles on therapy 35 Table 9. Assessment checklist for HTAs, systematic reviews, and meta-analyses 36 Table 10. Study quality assessment: Cochrane reviews of acute pain, labor pain, primary dysmenorrhea 38 Table 11. Study quality assessment: Cochrane reviews of chronic pain, chronic LBP, osteoarthritis of the knee and rheumatoid arthritis in the hand 39 Table 12. Study quality assessment: Cochrane reviews of cancer pain, chronic headache, neck disorders, and post-stroke shoulder pain 39 Table 13. Study quality assessment: New studies on acute pain (labor, primary dysmenorrhea) 40 Table 14. Study quality assessment: New studies on chronic pain 41 Table 15. TENS vs. sham TENS or control for labor pain: Pain- and satisfaction-related outcomes, with TENS applied either to the back or acupuncture points 49 Table 16. TENS vs. sham TENS: Labor and delivery outcomes, with TENS applied either to the back or acupuncture points 50 Table 17. TENS to the back vs. pharmacologic relief for treatment of labor pain 51 Table 18. Comparisons between TENS and placebo TENS, indicating for which analyses TENS was favored for treatment of osteoarthritis of the knee (pain relief measured by VAS 68 and patient-reported improvement) Table 19. Costing study, Chabal 1998 82 Table 20. Effectiveness measures used for cost simulation: Chabal 1998 83 Table 21. Overall results for cost simulations from Chabal 1998 83 Updated FINAL: ENS: 11-13-09 4 of 104 WA Health Technology Assessment - HTA LIST OF FIGURES Figure 1. Algorithm for article selection 33 Figure 2. Search results 34 Figure 3. Risk ratios for pain reduction of at least 50% and patient rating of excellent/good comparing TENS with sham TENS post-treatment based on three studies (one study 45 per comparison) Figure 4. Mean difference in pain intensity betwen TENS and placebo measured during a procedure, immediately post-treatment, or after 2 days of treatment 46 Figure 5. Mean difference in pain intensity for comparisons of TENS vs. control and high vs. low amplitude TENS, measured either during a procedure or post-treatment using a 47 numerical rating scale or visual analogue scale. Figure 6. HFTENS vs. placebo for dysmenorrhea: Pain relief (overall experience), adverse effects, and additional analgesic requirement (no. of women) 53 Figure 7. Weighted mean differences of pain relief (reduction in VAS score) , analgesic requirements (no. of pills), and lost hours from work/school for HFTENS compared to 54 placebo Figure 8. Positive overall experience with pain relief for LFTENS compared to placebo TENS and placebo pill for dysmenorrhea (Odds ratios, 95% CI) 55 Figure 9. Weighted mean differences of pain relief (reduction in VAS score), analgesic requirement (no. of pills), and lost hours from work/school for LFTENS compared to 56 placebo Figure 10. LFTENS vs. ibuprofen and naproxen: Pain relief, use of analgesics, and adverse events (Odds Ratio, 95% CI) 57 Figure 11. Proportion of studies of active TENS versus sham TENS for which an overall positive effect of TENS for relieving chronic pain (at different times post-treatment) was 59 described Figure 12. Evidence for analgesic efficacy after active HFTENS compared with sham TENS for the treatment of chronic pain over time 60 Figure 13. Mean difference in pain relief and pain intensity measured by VAS and pain improvement and pain frequency measured categorically in comparisons of conventional TENS +/ ALTENS vs. placebo at the end of 4 weeks treatment in a 62 study of 125 patients with chronic low back pain Figure 14. Mean differences in pain intensity and activity pain (measured by VAS) at the end of two weeks treatment in two studies of chronic low back pain 63 Figure 15. Mean differences in VAS pain relief experienced between TENS/ALTENS, TENS alone, ALTENS alone, HFTENS, high burst TENS and placebo 66 Figure 16. Comparison of pain improvement between TENS and placebo groups (reported categorically) immediately following treatment and during follow-up (Peto Odds 67 Ratio, 95% CI) Figure 17. Weighted mean difference in resting pain improvement and grip pain improvement comparing ALTENS to placebo after 3 weeks of treatment 71 Figure 18. Single treatment TENS vs. placebo for neck pain: standardized mean difference of % change in pain intensity and % change in trigger point tenderness 73 Figure 19. Multiple treatment TENS vs. placebo for neck pain: standardized mean difference of % change in pain intensity (1 study, n=20) (standardized mean difference, 95% CI) 74 Updated FINAL: ENS: 11-13-09 5 of 104 WA Health Technology Assessment - HTA Figure 20. Diadynamic (interferential) current therapy vs. placebo: Pain intensity and patient- rated improvement (number of patients reporting no pain/improved) after 5 days 75 treatment (RR, 95% CI) Figure 21. Reduction in VAS pain intensity from baseline: electrical stimulation vs. control and TENS vs. control (standard mean difference, 95% CI) 77 Figure 22. New reports of shoulder pain following treatment with ENS and TENS compared to control (Peto Odds Ratio, 95% CI; 2 studies) 78 Figure 23. Improvement in passive humeral lateral rotation (PHLR): ENS, TENS 79 and FES compared to control (Mean difference, 95% CI; 3 studies) Updated FINAL: ENS: 11-13-09 6 of 104 WA Health Technology Assessment - HTA EXECUTIVE SUMMARY INTRODUCTION According to the Centers for Disease Control and Prevention (CDC), pain is one of the most common causes of disability in the United States. The CDC’s National Center for Health Statistics reported in 2006 that one in four U.S. adults report a day-long bout of pain in the past month, and one in 10 say the pain lasted at least a year1. Low back pain, headache, and joint pain, aching or stiffness are among the most common complaints. Data from the 1999–2002 National Health and Nutrition Examination Survey (NHANES) revealed back pain to be the most commonly reported of all types, with more than 25% of adults reporting low back pain in the prior 3 months, with pain most commonly reported among adults 45 years of age and over.