Effective Date: 01/01/2012 Revision Date: Code(s): Application of surface (transcutaneous) neurostimulator

Transcription

1 ARBenefits Approval: 10/19/2011 Effective Date: 01/01/2012 Revision Date: Code(s): Application of surface (transcutaneous) neurostimulator Medical Policy Title: Electrical Stimulation, Transcutaneous Electrical Nerve Stimulator (TENS) Document: ARB0129 E0720 Transcutaneous electrical nerve stimulation (TENS) device, two lead, localized stimulation E0730 Transcutaneous electrical nerve stimulation (TENS) device, four or more leads, for multiple nerve stimulation Public Statement: Administered by: The use of TENS for chronic intractable pain is covered when medically necessary for the control of intractable chronic pain. Medical Policy Statement: A trial of transcutaneous electrical nerve stimulation (TENS) of at least 30 days, not to exceed 60 days, is considered medically necessary for the management of refractory chronic pain (e.g., chronic musculoskeletal or neuropathic pain) that causes significant disruption of function when the following conditions have been met: o o The pain is unresponsive to at least 3 months of conservative medical therapy; AND The trial is monitored by a physician. Continued use of transcutaneous electrical nerve stimulation (TENS) is medically necessary for treatment of refractory chronic pain (e.g., chronic musculoskeletal or neuropathic pain) that causes significant disruption of function when efficacy has been demonstrated in an initial therapeutic trial. Limits: Page 1 of 7

2 64550 is allowed no more than twice in one year. Background: Transcutaneous Electrical Nerve Stimulator (TENS) is an electronic device that applies electrical stimulation to the surface of the skin and the site of pain and has been used to relieve chronic intractable pain, post surgical pain and pain associated with active or post trauma injury unresponsive to other standard pain therapies. TENS consists of an electrical pulse generator, usually battery operated, connected by wire to two or more electrodes which are applied to the surface of the skin at the site of pain. The exact mechanism of action is unclear. A randomized, controlled trial from Taiwan assessed the efficacy of TENS applied at bilateral acupuncture points (Li4: midpoint between the first and second carpal bones, and Sp 6: 5 cm above the medial malleolus) in 100 women in the first stage of labor (5% dropout due to precipitous labor) (Chao, 2007). Additional medication was allowed, but was not reported. At the end of 30 minutes of treatment, the median VAS score improved in the active TENS group from 8 to 4.5 (10 mm scale), the VAS of the placebo group changed from 8 to 7. Pain relief of greater than 3 points was obtained in 62% of patients in the active group and 14% of patients in the sham group. The median duration of relief from pain following TENS acupuncture was 75 minutes. An industry-sponsored meta-analysis by Johnson and Martinson included 38 randomized controlled comparisons (1,227 patients from 29 publications) of trans- or percutaneous electrical nerve stimulation (ENS) for chronic musculoskeletal pain, using any stimulation parameters on any location (e.g., back, neck, hip, knee) (Johnson, 2007). The data were converted to a percentage improvement in VAS scores, then transformed into standardized mean differences (a continuous measure that adjusts for variability in different outcome measures). Based on the combined standardized difference, the authors concluded that TENS provided pain relief nearly three times the pain relief provided by placebo. There are a number of sources of bias in the analysis that seriously limit interpretation of the results. First, the heterogeneity of the individual study results (I2=82%) raises questions about the appropriateness of combining these studies in a meta-analysis (see previous discussion regarding the decision to not combine studies for the 2000 Cochrane review on chronic pain). Further limiting interpretation is the transformation of data to standardized effect size, which appears to have led to discrepant effect sizes of otherwise similar results. For example, comparison of the untransformed and transformed data shows that while two of the included trials (Deyo et al. 1990, and Machin et al. 1988), found similar percentage point differences in VAS between active and control groups (5% and 8%, respectively), the standardized effect sizes are not equivalent. Positive standardized effect sizes from data that are not statistically or clinically significant (e.g., 47% vs. 42% change from baseline in Deyo et al.) also raises concerns about the appropriateness of the data transformation. Inclusion of poor-quality studies is an additional concern, since several of the studies with the Page 2 of 7

3 greatest effect sizes reported drop-out rates exceeding 25%. Furthermore, bias for publication of small positive studies may not have been adequately addressed, since the Fail-safe N method used to assess publication bias is problematic. Another major limitation in interpretation of this meta-analysis is the absence of information about whether ENS results in a clinically meaningful improvement. For example, there was no discussion of the magnitude of the combined change in VAS scores or of the proportion of patients who achieved clinically meaningful improvements. Examination of the data indicates that there was less than a 15% difference between the ENS and placebo groups (with an average difference of 4%) for 13 of the 38 (34%) comparisons. The small effect observed in many of these small studies raises further questions about the contribution of publication bias to the meta-analysis. Also at issue is the relative contribution of percutaneous ENS (PENS), since meta-regression found PENS to be more effective than TENS. Given the substantial uncertainty regarding the appropriateness of the studies included and how the data were transformed, combined with questions regarding the clinical significance of the results, results from this metaanalysis are considered inconclusive. Data regarding clinical significance were provided in a meta-analysis by Bjordal et al. on the short-term efficacy of physical interventions for osteoarthritic knee pain (Bjordal, 2007). Included in the review were 11 studies (259 subjects on active therapy) using TENS, acupuncture-like TENS (AL-TENS), or interferential stimulation; 9 of the 11 studies were included in the meta-analysis reviewed above. Combined data revealed a 19 mm improvement in VAS over placebo (a slight improvement ), with a confidence interval ranging from 10 mm (a minimal perceptible improvement ) to 28 mm (above the 20 mm threshold of an important improvement ). These results are similar to an earlier Cochrane review (overlap of 6 studies) on the use of TENS or AL-TENS for osteoarthritis of the knee (Osiri, 2002). The inclusion of 2 studies on interferential stimulation (with an unweighted average improvement in VAS of 34 mm over placebo) may also have increased the magnitude of the effect. Considering that the potential for publication bias is high when combining a number of small studies in a meta-analysis (particularly when the effect is small), evidence of short-term relief of chronic musculoskeletal pain remains weak. Results from these positive meta-analyses must also be balanced against other systematic reviews of musculoskeletal pain syndromes that found mixed and inconclusive results. A recent randomized sham-controlled trial (n=163) reported that although no differences in VAS pain scores were observed, more patients were satisfied following 10 days (10-12 hours/day) of TENS (58%) than following use of a sham device (43%) (Oosterhof, 2006). Analysis of the results by type of pain (osteoarthritis-related, neuropathic, or bone/soft tissue/visceral) in a subsequent report showed no difference in patient satisfaction for the group with osteoarthritis and related disorders (39% vs. 31%, n = 31, 26) or in patients with neuropathic pain (63% vs. 48%, n = 16, 25), and greater satisfaction with TENS in the group of patients with injury of bone and soft tissue or visceral pain (74% vs. 48%, n = 34, 31). The nearly 50% patient satisfaction rating in the sham control group suggests a strong nonspecific effect with this treatment protocol. Page 3 of 7

4 Professional/Scientific Organization Positions According to the Agency for Healthcare Research and Quality (AHRQ) Guidelines Clearinghouse, the Department of Veterans Affairs published a guideline on management of low back pain or sciatica in the primary care setting. The report stated that Evidence is insufficient to recommend transcutaneous electrical nerve stimulation (TENS) in the treatment of patients with acute low back pain. The American Geriatrics Society produced a guideline in 1998, stating that transcutaneous nerve stimulation may be helpful for some patients, but they are expensive and have not been shown to have greater benefit than placebo controls in the management of chronic pain. (Ferrell, 2009) The American Medical Directors Association created a guideline in 1999 on management of pain for elderly patients in the long-term care setting. Among complementary therapies, transcutaneous electrical nerve stimulation is one for which Although no scientific evidence supports the effectiveness of these therapies in elderly patients in the long-term care setting, they may be beneficial to some individuals. The Department of Defense, Veterans Health Administration, published clinical guidelines for the management of postoperative pain in May These guidelines indicate that TENS may be useful for postoperative pain relief for a variety of procedures and sites. Except for postoperative abdominal pain and pain from cholecystectomy, all of the recommendations are consensus based. For postoperative abdominal pain and pain from cholecystectomy, the recommendations are based on at least 1 RCT and general agreement that TENS is acceptable. The AHRQ Guidelines Clearinghouse also lists several other guidelines that indicate TENS may be used for management of pain. However, none of these guidelines lists TENS as a major recommendation. The American Pain Society and American College of Physicians published guidelines on therapies for acute and low back pain in 2007 (Chou, 2007). No recommendations for TENS were made; evidence was found to be insufficient to assess the efficacy of TENS in comparison with other interventions. The European Federation of Neurological Societies published 2007 guidelines on neurostimulation for neuropathic pain Cruccu, 2007). The task force was not able to arrive at conclusive recommendations, with only about 200 patients with different diseases, in studies using different parameters and comparators, and with variable results. The task force concluded that standard high-frequency TENS is possibly (level C) better than placebo, and probably (level B) worse than acupuncture-like or any other kind of electrical stimulation. Page 4 of 7

5 Three additional Cochrane reviews were published in 2008, addressing the topics of TENS for cancer pain, chronic low back pain, and other chronic pain conditions (Robb, 2008) (Khadikar, 2008) Nnoaham, 2008). For cancer pain, only 2 RCTs (total of 64 participants) met the selection criteria for inclusion in the systematic review (Robb, 2008). There were no significant differences between TENS and placebo in the included studies, and results of the review were considered inconclusive due to a lack of suitable RCTs. For the treatment of chronic low back pain, 4 high-quality RCTs (585 patients) met the selection criteria (Khadikar, 2008). There was conflicting evidence about whether TENS reduced back pain and consistent evidence from 2 of the trials (410 patients) that it did not improve back-specific functional status. The review concluded that the evidence available at this time does not support the use of TENS in the routine management of chronic low back pain. An updated review of TENS for the treatment of various other chronic pain conditions including rheumatoid arthritis with wrist pain, temporomandibular joint dysfunction, multiple sclerosis with back pain, osteoarthritis with knee pain, neuropathy, pancreatitis, and myofascial trigger points included 25 RCTs (1281 patients) (Nnoaham, 2008). Due to heterogeneity, meta-analysis was not possible; slightly over half of the studies found a positive analgesic outcome in favor of active TENS treatments. The authors concluded that the 6 studies added since the last version of this review did not provide sufficient additional information to change the conclusions, and that the published literature lacks the methodological rigor needed to make confident assessments of the role of TENS in chronic pain management. Recent literature suggests that TENS may alleviate acute pain. For example, one double-blind randomized, sham-controlled trial found that during emergency transport of 101 patients, TENS reduced post-traumatic hip pain with a change in visual analog scale (VAS) from 89 to 59, whereas the sham-stimulated group remained relatively unchanged (86 to 79) (Lang, 2007). In another double-blind study, 40 patients undergoing inguinal herniorrhaphy were randomized to active or placebo TENS for postsurgical pain (De Santana, 2008). Pain scores measured prior to the first treatment were 5.2 on a 10 point scale for the active TENS group and 5.3 for the placebo TENS group. Two 30-minute sessions of TENS at 2 and 4 hours after surgery reduced both analgesic use and pain scores measured up to 24 hours after surgery (mean pain score of 0 vs. 3.4). Blinding appears to have been maintained, as 95% of subjects from both groups reported that they would use TENS again in the future to treat their pain. Confirmation of these results is needed. Overall, evidence for the use of TENS from high quality trials remains inconclusive. However, expert opinion received indicates that the use of TENS for the relief of chronic intractable pain has been beneficial in some patients. References: Bjordal JM, Johnson MI, Lopes-Martins RA et al.(2007) Short-term efficacy of physical interventions in osteoarthritic knee pain. A systematic review and meta-analysis of Page 5 of 7

6 randomised placebo-controlled trials. BMC Musculoskelet Disord 2007; 8:51. Carroll D, Moore RA, McQuay HJ et al.(2002) Transcutaneous electrical nerve stimulation (TENS) for chronic pain (Cochrane Review). The Cochrane Library, Issue 3, Oxford: Update Software. Chao AS, Chao A, Wang TH et al.(2007) Pain relief by applying transcutaneous electrical nerve stimulation (TENS) on acupuncture points during the first stage of labor: a randomized double-blind placebo-controlled trial. Pain 2007; 127(3): Chou R, Qaseem A, Snow V et al.(2007) Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society.. Ann Intern Med 2007; 147(7): Cruccu G, Aziz TZ, Garcia-Larrea L et al.(2007) EFNS guidelines on neurostimulation therapy for neuropathic pain. Eur J Neurol 2007; 14(9): DeSantana JM, Walsh DM, Vance C et al.(2008) Effectiveness of transcutaneous electrical nerve stimulation for treatment of hyperalgesia and pain. Curr Rheumatol Rep 2008; 10(6): Deyo RA, Walsh NE, Martin DC et al.(1990) A controlled trial of transcutaneous electrical nerve stimulation (TENS) and exercise for chronic low back pain. N Engl J Med 1990; 322(23): Ferrell B, Casarett D, Epplin J et al.(2002) The AGS Guideline on the Management of Persistent Pain in Older Persons. J Am Geriatr Soc 2002; 50(6 Suppl):S Available at: Johnson M, Martinson M.(2007) Efficacy of electrical nerve stimulation for chronic musculoskeletal pain: a meta-analysis of randomized controlled trials. Pain 2007; 130(1-2): Khadilkar A, Odebiyi DO, Brosseau L et al.(2008) Transcutaneous electrical nerve stimulation (TENS) versus placebo for chronic low-back pain. Cochrane Database Syst Rev 2008; (4):CD Lang T, Barker R, Steinlechner B et al.(2007) TENS relieves acute posttraumatic hip pain during emergency transport. J Trauma 2007; 62(1): Machin D, Lewith GT, Wylson S.(1998) Pain measurement in randomized clinical trials: a comparison of two pain scales. Clin J Pain 1988; 4: Milne S, Welch V, et al.(2003) Transcutaneous electical nerve stimulation (TENS) for chronic low back pain (Cochrane Review). Cochrane Library, Issue 4, Nnoaham KE, Kumbang J.(2008) Transcutaneous electrical nerve stimulation (TENS) Page 6 of 7

7 for chronic pain. Cochrane Database Syst Rev 2008; (3):CD Oosterhof J, De Boo TM, Oostendorp RA et al.(2006) Outcome of transcutaneous electrical nerve stimulation in chronic pain: short-term results of a double-blind, randomised, placebo-controlled trial. J Headache Pain 2006; 7(4): Oosterhof J, Samwel HJ, de Boo TM et al.(2008) Predicting outcome of TENS in chronic pain: A prospective, randomized, placebo controlled trial. Pain 2008; 136(1-2): Osiri M, Welch V, Brosseau L et al.(2002) Transcutaneous electrical nerve stimulation for knee osteoarthritis (Cochrane Review). In: The Cochrane Library, 2002(4):CD Proctor ML, Smith CA, Farquhar CM et al.(2002) Transcutaneous electrical nerve stimulation and acupuncture for primary dysmenorrhoea (Cochrane Review). In: The Cochrane Library, 2002; (1):CD Robb KA, Bennett MI, Johnson MI et al.(2008) Transcutaneous electric nerve stimulation (TENS) for cancer pain in adults. Cochrane Database Syst Rev 2008; (3):CD Application to Products This policy applies to ARBenefits. Consult ARBenefits Summary Plan Description (SPD) for additional information. Last modified by: Date: Page 7 of 7