Transcutaneous Electrical Nerve Stimulation for Chronic Low Back Pain

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A. Definitions For the purposes of this decision CLBP is defined as: an episode of low back pain that has persisted for three months or longer; and is not a manifestation of a clearly defined and generally recognizable primary disease entity. For example, there are cancers that, through metastatic spread to the spine or pelvis, may elicit pain in the lower back as a symptom; and certain systemic diseases such as rheumatoid arthritis and multiple sclerosis manifest many debilitating symptoms of which low back pain is not the primary focus. B. TENS is not reasonable and necessary for the treatment of CLBP under section 1862(a)(1)(A) of the Social Security Act. C. In order to support additional research on the use of TENS for CLBP, we will cover this item under section 1862(a)(1)(E) of the Social Security Act subject to all of the following conditions. Coverage under this section C expires three years after the publication of this decision on the CMS website. The beneficiary is enrolled in an approved clinical study meeting all of the requirements below. The study must address one or more aspects of the following questions in a randomized, controlled design using validated and reliable instruments. This can include randomized crossover designs when the impact of prior TENS use is appropriately accounted for in the study protocol. Does the use of TENS provide clinically meaningful reduction in pain in Medicare beneficiaries with CLBP? Does the use of TENS provide a clinically meaningful improvement of function in Medicare beneficiaries with CLBP? Does the use of TENS impact the utilization of other medical treatments or services used in the medical management of CLBP? These studies must be designed so that the patients in the control and comparison groups receive the same concurrent treatments and either sham (placebo) TENS or active TENS intervention. The study must adhere to the following standards of scientific integrity and relevance to the Medicare population: The principal purpose of the research study is to test whether a particular intervention potentially improves the participants’ health outcomes. The research study is well supported by available scientific and medical information or it is intended to clarify or establish the health outcomes of interventions already in common clinical use. The research study does not unjustifiably duplicate existing studies. The research study design is appropriate to answer the research question being asked in the study. The research study is sponsored by an organization or individual capable of executing the proposed study successfully. The research study is in compliance with all applicable Federal regulations concerning the protection of human subjects found at 45 CFR Part 46. If a study is regulated by the Food and Drug Administration (FDA), it must be in compliance with 21 CFR parts 50 and 56. All aspects of the research study are conducted according to appropriate standards of scientific integrity (see http://www.icmje.org). The research study has a written protocol that clearly addresses, or incorporates by reference, the standards listed here as Medicare requirements for CED coverage. The clinical research study is not designed to exclusively test toxicity or disease pathophysiology in healthy individuals. Trials of all medical technologies measuring therapeutic outcomes as one of the objectives meet this standard only if the disease or condition being studied is life threatening as defined in 21 CFR § 312.81(a) and the patient has no other viable treatment options. The clinical research study is registered on the ClinicalTrials.gov website by the principal sponsor/investigator prior to the enrollment of the first study subject. The research study protocol specifies the method and timing of public release of all prespecified outcomes to be measured including release of outcomes if outcomes are negative or study is terminated early. The results must be made public within 24 months of the end of data collection. If a report is planned to be published in a peer reviewed journal, then that initial release may be an abstract that meets the requirements of the International Committee of Medical Journal Editors (http://www.icmje.org). The research study protocol must explicitly discuss subpopulations affected by the treatment under investigation, particularly traditionally underrepresented groups in clinical studies, how the inclusion and exclusion criteria effect enrollment of these populations, and a plan for the retention and reporting of said populations on the trial. If the inclusion and exclusion criteria are expected to have a negative effect on the recruitment or retention of underrepresented populations, the protocol must discuss why these criteria are necessary. The research study protocol explicitly discusses how the results are or are not expected to be generalizable to the Medicare population to infer whether Medicare patients may benefit from the intervention. Separate discussions in the protocol may be necessary for populations eligible for Medicare due to age, disability or Medicaid eligibility. Consistent with section 1142 of the Social Security Act, AHRQ supports clinical research studies that CMS determines meet the above-listed standards and address the above-listed research questions.

Decision Memo: To: Administrative File: (CAG #00429N) From: Louis Jacques, MD Director, Coverage and Analysis Group Tamara Syrek Jensen, JD Deputy Director, Coverage and Analysis Group James Rollins, MD, MSHA, PhD Director, Division of Items and Devices Brijet Burton, MPP, MS, PA-C Lead Analyst, Division of Items and Devices Rosemarie Hakim, PhD Epidemiologist Susan Miller, MD Lead Medical Officer Subject: Final Decision Memorandum for Transcutaneous Electrical Nerve Stimulation for Chronic Low Back Pain (CAG-00429N) Date: June 8, 2012 I. Final Decision: A. Definitions For the purposes of this decision CLBP is defined as: an episode of low back pain that has persisted for three months or longer; and is not a manifestation of a clearly defined and generally recognizable primary disease entity. For example, there are cancers that, through metastatic spread to the spine or pelvis, may elicit pain in the lower back as a symptom; and certain systemic diseases such as rheumatoid arthritis and multiple sclerosis manifest many debilitating symptoms of which low back pain is not the primary focus. B. TENS is not reasonable and necessary for the treatment of CLBP under section 1862(a)(1)(A) of the Social Security Act. C. In order to support additional research on the use of TENS for CLBP, we will cover this item under section 1862(a)(1)(E) of the Social Security Act subject to all of the following conditions. Coverage under this section C expires three years after the publication of this decision on the CMS website. The beneficiary is enrolled in an approved clinical study meeting all of the requirements below. The study must address one or more aspects of the following questions in a randomized, controlled design using validated and reliable instruments. This can include randomized crossover designs when the impact of prior TENS use is appropriately accounted for in the study protocol. Does the use of TENS provide clinically meaningful reduction in pain in Medicare beneficiaries with CLBP? Does the use of TENS provide a clinically meaningful improvement of function in Medicare beneficiaries with CLBP? Does the use of TENS impact the utilization of other medical treatments or services used in the medical management of CLBP? These studies must be designed so that the patients in the control and comparison groups receive the same concurrent treatments and either sham (placebo) TENS or active TENS intervention. The study must adhere to the following standards of scientific integrity and relevance to the Medicare population: The principal purpose of the research study is to test whether a particular intervention potentially improves the participants’ health outcomes. The research study is well supported by available scientific and medical information or it is intended to clarify or establish the health outcomes of interventions already in common clinical use. The research study does not unjustifiably duplicate existing studies. The research study design is appropriate to answer the research question being asked in the study. The research study is sponsored by an organization or individual capable of executing the proposed study successfully. The research study is in compliance with all applicable Federal regulations concerning the protection of human subjects found at 45 CFR Part 46. If a study is regulated by the Food and Drug Administration (FDA), it must be in compliance with 21 CFR parts 50 and 56. All aspects of the research study are conducted according to appropriate standards of scientific integrity (see http://www.icmje.org). The research study has a written protocol that clearly addresses, or incorporates by reference, the standards listed here as Medicare requirements for CED coverage. The clinical research study is not designed to exclusively test toxicity or disease pathophysiology in healthy individuals. Trials of all medical technologies measuring therapeutic outcomes as one of the objectives meet this standard only if the disease or condition being studied is life threatening as defined in 21 CFR § 312.81(a) and the patient has no other viable treatment options. The clinical research study is registered on the ClinicalTrials.gov website by the principal sponsor/investigator prior to the enrollment of the first study subject. The research study protocol specifies the method and timing of public release of all prespecified outcomes to be measured including release of outcomes if outcomes are negative or study is terminated early. The results must be made public within 24 months of the end of data collection. If a report is planned to be published in a peer reviewed journal, then that initial release may be an abstract that meets the requirements of the International Committee of Medical Journal Editors (http://www.icmje.org). The research study protocol must explicitly discuss subpopulations affected by the treatment under investigation, particularly traditionally underrepresented groups in clinical studies, how the inclusion and exclusion criteria effect enrollment of these populations, and a plan for the retention and reporting of said populations on the trial. If the inclusion and exclusion criteria are expected to have a negative effect on the recruitment or retention of underrepresented populations, the protocol must discuss why these criteria are necessary. The research study protocol explicitly discusses how the results are or are not expected to be generalizable to the Medicare population to infer whether Medicare patients may benefit from the intervention. Separate discussions in the protocol may be necessary for populations eligible for Medicare due to age, disability or Medicaid eligibility. Consistent with section 1142 of the Social Security Act, AHRQ supports clinical research studies that CMS determines meet the above-listed standards and address the above-listed research questions. II. Background Low back pain (LBP) is a widespread complaint in the United States. It is the fifth most common complaint for which professional health care advice is sought [Rathmell 2008; Chou 2010]. Approximately 75-80% of individuals in the United States will experience an episode of LBP in their lifetime; there is a 5% annual incidence of the condition [Weinstein 2005]. It is estimated that greater than 17 million elderly individuals experience at least one episode of LBP in a year in the U.S. [Morone 2009]. In a minority of patients, a medical history, physical examination, and appropriate laboratory/imaging studies can identify causes such as cancer, infection, compression fractures and inflammatory arthropathies such as ankylosing spondylitis. However, there is no well-defined etiology of the pain in approximately 85% of individuals who present with LBP [Negrini 2010]. For most people, LBP is a short-lived condition whether or not treatment is provided, lasting less than 12 weeks for 80-90% of those who experience it. However, a small but significant proportion of individuals, approximately 10 – 20%, will experience a continuation of LBP with disabling symptoms [Rathmell 2008; Chou 2010]. Many authors define persistent LBP lasting greater than or equal to 12 weeks or 3 months to be chronic [Khadilkar 2005; Machado 2008; Poitras 2007; van Middelkoop 2011]. We also, for the purposes of this decision memorandum, define CLBP as LBP that has persisted at least three months. Proposed treatment regimens for CLBP include a range of interventions including physical therapy, behavioral therapy, TENS, drug therapy, and surgery. Examples of physical therapy treatments include exercise therapy, traction, and body biomechanics education. These treatments are meant to reduce pain, inflammation, and muscle spasm, as well as increase strength and range of motion, and improve functional status. TENS involves the delivery of electric current to the skin through surface electrodes, primarily for the intended purpose of pain relief. TENS has been used as a therapy for musculoskeletal pain in many anatomic sites of the body; it has also been used to treat post-surgical pain, labor pain, primary dysmenorrhea, as well as the pain associated with a host of other medical conditions. TENS units are usually small, portable battery operated devices that deliver electrical current to the skin through electrodes. They are usually administered by a therapist in a clinical setting, and then self-administered by the patient, once adequately instructed. Usually, several skilled therapy sessions are required to establish the optimal stimulation settings and sites of electrode placement for a patient. In clinical practice, the electrical characteristics of TENS units are varied among the devices used and the clinicians who apply them [Knight 2008]. Two examples of commonly used approaches are a frequency greater than 50 Hz (i.e., conventional or traditional TENS) or a frequency of 1-10 Hz (low frequency or acupuncture-like TENS) [Sluka 2009]. Conventional TENS is usually perceived by a patient as a tingling sensation, while low frequency or acupuncture-like TENS is experienced as a burning, needling sensation [Knight 2008]. TENS devices can also be configured to deliver different types of output patterns for individual patients, including those that produce constant pulses, and those that provide repetitive trains or bursts of electrical pulses delivered in a limited time period, followed by a specified period of no current flow. Moreover, a TENS device may also be configured to produce a modulated output, so that one or several of the parameters of the electrical stimulation are cyclically changed during a single application of treatment [Sluka 2009]. A variant of TENS, also included in this review, is interferential current (IFC) therapy. This form of treatment applies two separate medium frequency (2000 – 4000 Hz) sinusoidal currents to the skin simultaneously. These two currents can then be superimposed upon each other, so that the resultant current is different from either of the initiating currents. The rationale behind the application of dual electric currents is based on the fact that the impedance (or resistance) of skin and subcutaneous tissue is inversely proportional to the frequency of stimulation. Therefore, there is less resistance to current at 3000 Hz than there is at 300 Hz. Proponents of IFC therapy state that the combined currents will pass more easily through the skin and reach deeper levels of tissues producing stronger physiologic effects, while at the same time causing less discomfort than would be required by other forms of TENS [Knight 2008; Sluka 2009]. There are several theories that have been hypothesized to support the clinical use of TENS for pain relief. Originally, the Melzack and Wall gate theory of pain was considered as the foundation of the mechanism of action for TENS. In this theory, a “gate” in the dorsal horn of the spinal cord has the capacity to inhibit transmission of nociceptive stimulation to the ascending tracts of the nervous system. By using TENS to activate the large diameter afferent nerves of the peripheral nervous system, it was believed that these devices could block the noxious painful sensations that were being felt by the patient [Walsh 2010]. However, as more research has accumulated, investigators now believe that TENS may produce pain relief by activating the supraspinal nervous system as well as the afferent nerves that affect the spine. These effects are proposed to occur at least in part, due to the modulation of the body’s endogenous chemicals (e.g., endorphins, glutamate, etc.) that affect the perception of pain [DeSantana 2008(b); Sluka 2009]. Some also claim that the use of TENS causes a local dilatation of blood vessels in injured tissues [Noble 2000], that might mitigate nociceptive sensations. For purposes of research conducted to determine the effectiveness of TENS, pain measurement tools usually incorporate the use of scales and questionnaires. Using these measures, improvement or worsening of pain symptomatology can be tracked over time. Among the tools commonly used to quantify pain are: Number scales – Used to measure pain intensity, these scales consist of a range of numbers (e.g., 0 – 100) with descriptors providing general correlative indications (e.g., 0 = no pain; 100 = maximal pain). Subjects are asked to identify the number that best describes their pain. Visual analog scale (VAS) – A VAS is an unnumbered line, frequently 100 mm in length,with contrasting descriptors at either end. The descriptors could be for example, no pain/worst pain, sharp/dull, etc. The patient is asked to make a vertical mark at the point along the continuum that best represents their pain level. The investigator measures the distance of the patient’s marking from the left side of the line; this measure denotes the pain score [Knight 2008]. Investigators have also attempted to measure the effects of pain reduction or worsening through the use of questionnaires that gather patient perceptions of their activity and disability status. Examples of such outcomes instruments include: Oswestry disability index (ODI) – The ODI is used to determine those activities of daily living (e.g., standing, walking, lifting, sitting, and personal care) that are disturbed by the presence of low back pain. Each item is answered on the basis of pain being experienced “today.” The ODI can be self-administered [Ostelo 2005]. Roland Morris Disability Questionnaire (RDQ) – The RDQ is a condition-specific health status measurement tool created to assess physical function in individuals with low back pain. Patients select from 24 items that describe their current activities/limitations (e.g., walking, standing, bending/kneeling, sleeping, etc.) due to their back pain “today.” The RDQ can be self-administered [Ostelo 2005]. McGill Pain Questionnaire – This questionnaire is a self-administered tool. Patients draw the location of their pain on a body diagram and use the listed pain descriptors and pain scales to express the characteristics and magnitude of their discomfort [Knight 2008]. Additionally, indirect measures such as strength, range of motion and physical functioning may be used to determine the effectiveness of pain interventions. III. History of Medicare Coverage Current National Coverage Determinations (NCDs) For the convenience of the reader, we note the Medicare National Coverage Determinations Manual has a number of NCDs addressing several uses of TENS in various settings including home use and supervised use outside the home. Transcutaneous Electrical Nerve Stimulation (TENS) for Acute Post-Operative Pain (10.2) Assessing Patient’s Suitability for Electrical Nerve Stimulation Therapy (160.7.1) Supplies Used in the Delivery of Transcutaneous Electrical Nerve Stimulation (TENS) and Neuromuscular Electrical Stimulation (NMES) (160.13) Transcutaneous Electrical Nerve Stimulators (TENS) (280.13) Current Request CMS generated this request internally. We limited our review to CLBP as defined above. We specifically excluded certain well-defined diseases that may contribute to low back pain but which are not primarily low back syndromes. For example, there are cancers that, through metastatic spread to the spine or pelvis, may elicit pain in the lower back as a symptom. Certain systemic diseases such as rheumatoid arthritis, multiple sclerosis, etc, manifest many debilitating symptoms of which low back pain is not the primary focus. We believe that the appropriate management of these types of diseases is guided by a systematic strategy aimed at the underlying causes. While TENS may infrequently be used adjunctively in managing the symptoms of these diseases, it is clearly not the primary therapeutic approach. Benefit Category Medicare is a defined benefit program. An item or service must fall within a benefit category as a prerequisite to Medicare coverage, §1812 (Scope of Part A); §1832 (Scope of Part B) §1861(s) (Definition of Medical and Other Health Services). Transcutaneous electrical nerve stimulation is durable medical equipment (DME), as referenced in §1861(s)(6) of the Act. This may not be an exhaustive list of all benefit categories for TENS. IV. Timeline of Recent Activities Date Action September 13, 2011 CMS posts a tracking sheet and opens a National Coverage Determination (NCD). The initial 30-day public comment period begins. October 13, 2011 Initial public comment period ended. CMS received a total of 359 comments. March 13, 2012 CMS posts the proposed decision memorandum for 30 days of public comment. April 12, 2012 The public comment period on the proposed decision memorandum closes with 275 comments received. V. FDA Status Because the TENS device was marketed prior to the 1976 Medical Device Amendments to the Federal Food, Drug, and Cosmetic Act, its market approval was “grandfathered” rather than the result of satisfying the requirements of the PMA regime. We understand that TENS units are cleared under 510(k) for marketing, and that TENS for pain relief has never been PMA approved. Since TENS for pain relief has only been 510(k) cleared and not PMA approved, it has not been found to have a reasonable assurance of safety and effectiveness (the PMA standard); therefore it has not been found by FDA to be effective/have clinical benefit for pain relief. VI. General Methodological Principles In general, when making NCDs under §1862(a)(1)(A), CMS evaluates relevant clinical evidence to determine whether or not the evidence supports a finding that an item or service falling within a benefit category is reasonable and necessary for the diagnosis or treatment of illness or injury or improves the functioning of a malformed body member. The critical appraisal of the evidence enables us to determine to what degree we are confident that: 1) the specific assessment questions can be answered conclusively; and 2) the intervention will improve health outcomes for Medicare beneficiaries. An improved health outcome is one of several considerations in determining whether an item or service is reasonable and necessary under §1862(a)(1)(A) of the Act. A detailed account of the methodological principles of study design that are used to assess the relevant literature on a therapeutic or diagnostic item or service for specific conditions can be found in Appendix B. In general, features of clinical studies that improve quality and decrease bias include the selection of a clinically relevant cohort, the consistent use of a single good reference standard, the blinding of readers of the index test, and reference test results. Public comments sometimes cite the published clinical evidence and give CMS useful information. Public comments that give information on unpublished evidence such as the results of individual practitioners or patients are less rigorous and therefore less useful for making a coverage determination. VII. Evidence A. Introduction This section provides a summary of the evidence we considered during our review. The evidence reviewed to date in this NCA includes the published medical literature on pertinent clinical trials of TENS for CLBP. B. Discussion of Evidence Reviewed 1. Questions In order to determine if TENS improves the health outcomes of Medicare beneficiaries with CLBP, we pose the following questions: Does the use of TENS produce a clinically meaningful reduction in pain in Medicare beneficiaries with CLBP? Does the use of TENS produce a clinically meaningful improvement in function in Medicare beneficiaries with CLBP? Does the use of TENS produce a clinically meaningful, improvement in any other health outcome in Medicare beneficiaries with CLBP? If the answer to any of the questions above is affirmative, is the evidence sufficient to confidently identify the patient or device characteristics that predict improved health outcomes? 2. External Technology Assessment An external technology assessment was not commissioned for this review. 3. Internal Technology Assessment Systematic reviews are based on a comprehensive search of published studies to answer a clearly defined and specific set of clinical questions. A well-defined strategy or protocol (established before the results of the individual studies are known) guides this literature search. Thus, the process of identifying studies for potential inclusion and sources for finding such articles is explicitly documented at the start of the review. Finally, systematic reviews provide a detailed assessment of the studies included. Literature search methods We searched the PUBMED and EMBASE databases, the Cochrane Library, and the National Guidelines Clearinghouse up to August 2011. Search terms included ‘TENS for chronic low back pain’ and ‘transcutaneous electrical nerve stimulation for chronic low back pain.’ We identified those studies with and without randomized control trial (RCT) design, meta-analyses and systematic reviews. Of the references found, we read through the abstracts and titles to find those that met the criteria below. We also reviewed references submitted to us by commenters and performed a hand search of bibliographies to identify other pertinent articles. For the purpose of this analysis, we reviewed clinical trials with the following inclusion criteria: Adults with chronic low back pain (with or without leg pain) present for 3 months or greater Studies with ten or more patients Trials with well-defined comparators Studies where participants used TENS over a period of at least 4 weeks All models, frequencies, and wave patterns of TENS applied superficially to the skin Studies including data on individuals who experienced less than 3 months of pain or reported outcomes after less than 4 weeks of TENS treatment were included if subgroup analyses were performed meeting the criteria as above. We excluded studies that examined chronic low back pain in individuals with pain related to malignancy, neurodegenerative diseases (e.g. multiple sclerosis), and well-defined rheumatic disorders (except for osteoarthritis). Systematic reviews and meta-analyses that had as their main objective, either in part or in whole, a comparison of TENS versus sham TENs and/or other therapies for patients with chronic low back pain from the year 2005 forward were also included in our review. Those that discussed the use of TENS in the treatment of combined musculoskeletal conditions or in combined acute/chronic LBP were excluded if subgroup analyses were not performed within our parameters of interest. Based on the criteria noted above, CMS has found a limited number of studies (see Table 2 for articles excluded from review). The pertinent rationale for our inclusion/exclusion criteria is twofold: (1) CMS did not in this NCA include all potential uses of TENS. Uses of TENS that fall outside the scope of analysis are not impacted by our review, and thus we excluded studies of LBP associated with neurodegenerative (e.g. multiple sclerosis) disease, malignancy, or well-defined rheumatic disorders (except osteoarthritis). (2) Furthermore, while LBP complaints are common, studies indicate that about 80% of lower back pain resolves in approximately 6 weeks, leaving 10-20% of those individuals experiencing this complaint to have discomfort that is more long-lasting [Rathmell 2008 and Chou 2010]. CMS defines chronic low back pain (CLBP), for the purpose of this NCD, as pain that persists for 3 months or longer. Using this definition, we believe that individuals with CLBP can experience pain for years or even for a lifetime. Thus we focused on evidence that addressed use over a comparable time period. Systematic Reviews and Meta-analyses Dubinsky R, Miyasaki J. Assessment: Efficacy of transcutaneous electric nerve stimulation in the treatment of pain in neurologic disorders (an evidence-based review). Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology . 2010;74:173-176. This systematic review summarizes the evidence on the efficacy of TENS in the treatment of pain associated with neurologic disorders, including CLBP. The authors searched MEDLINE and the Cochrane Library for clinical trials of more than ten patients that compared TENS to placebo or to another therapy to treat low back pain of differing etiologies, including multiple sclerosis. The authors noted that there were varied definitions among the included clinical trials for meaningful reduction in pain. Five studies were evaluated. The review concluded that there was conflicting evidence for the use of TENS in the treatment of CLBP and that TENS should be deemed ineffective for this purpose. Khadilkar A, Milne S, ,Brosseau L, Robinson V, Saginur M, Shea B, Tugwell P, Wells G. Transcutaneous electrical nerve stimulation (TENS) for chronic low-back pain. The Cochrane Database of Systematic Reviews , 2005, Issue 3. Art. No.:CD003008. DOI: 10. 1002/14651858. CD003008. pub2. The main objective of this systematic review was to determine the effectiveness of transcutaneous electrical nerve stimulation in the treatment of chronic low back pain. A secondary goal was to determine the most effective parameters to administer TENS. These parameters could include stimulation factors, sites of application, application techniques and duration of treatment. The authors searched MEDLINE from 1966 to April 2005; EMBASE, and the Physiotherapy Evidence Database (PEDro) up to April 2005; and the Cochrane Controlled Trials Register, Issue 1, 2005. The authors included randomized controlled trials of outpatients 18 years old and above, with a diagnosis of chronic (greater than 12 weeks), mechanical low back pain. Patients with signs and symptoms of sciatic pain or a previous history of back surgery were not excluded. However, patients with malignancy, infection, inflammatory disorder or neurological syndromes were specifically excluded. All standard models of TENS were included and sham TENS was considered an acceptable placebo. Studies in which patients were provided TENS treatment percutaneously with acupuncture needles were excluded. Only 2 articles met the inclusion criteria of this review. The authors concluded that the evidence provided inconsistent support for the use of TENS as an isolated treatment modality in the treatment of CLBP. Khadilkar A, Odebiyi DO, Brosseau L, Wells GA. Transcutaneous electrical nerve stimulation (TENS) versus placebo for chronic low-back pain . Cochrane Database of Systematic Reviews , 2008, Issue 4. Art. No.:CD003008. DOI: 10. 1002/14651858. CD003008. pub3. The main objective of this systematic review was to determine whether transcutaneous electrical nerve stimulation is more effective for the treatment of chronic low back pain than placebo. Initially the authors searched MEDLINE from 1966 to April 2005; EMBASE, and the Physiotherapy Evidence Database (PEDro) up to April 2005; and the Cochrane Controlled Trials Register, Issue 1, 2005 (see above). For this update, they searched MEDLINE, EMBASE and PEDro from 2004 to July 19, 2007. They also searched CINHAL from its initiation until July 19, 2007, and the Cochrane Controlled Trials Register, Issue 3, 2007. Additionally, the International Clinical Trials Registry was searched for ongoing trials. The authors included randomized controlled trials of subjects aged 18 and over in which more than five LBP patients per treatment group were present. CLBP was defined as persistent pain, lasting more than 12 weeks, located between the inferior gluteal fold and the costal margin. Studies with subjects experiencing pain from malignancy, infection, fracture, inflammatory disorder or neurological syndromes were excluded. Studies that included subjects with a previous history of back surgery or signs and symptoms of sciatica were not excluded; however these types of patients had to represent a minority of the study sample in order for the article to qualify for review. Studies that investigated LBP of less than 12 weeks duration or of middle/upper back pain were excluded from the review unless data were presented separately for the population of interest. All standard models of TENS were included in the review, but not articles in which percutaneous delivery of the electrical stimulation was performed. The placebo TENS device accepted was one in which generally the TENS device was modified so that no electric current passed to the skin through the electrodes. Furthermore, comparisons of TENS to other treatment modalities were not considered by the authors. The outcome measures of greatest interest consisted of pain, functional status, generic health status, patient satisfaction and side effects. Secondary outcome measures consisted of physical examination measurements, medication use and use of medical services. The authors established values to define minimal clinically important differences in pain scores and functional outcomes. When statistical pooling of data was not possible, the authors defined a criterion for consistency of findings among the included studies. The authors found four trials to meet their criteria for review. They concluded that these trials failed to consistently demonstrate that TENS relieves the symptoms and reduces the disability associated with CLBP. Machado L, Kamper S, Herbert R, Maher C, McAuley J. Analgesic effects of treatments for non-specific low back pain: a meta-analysis of placebo-controlled randomized trials. Rheumatology . 2009; 48:520-527. The goal of this article was to perform a systematic review and meta-analysis of placebo controlled randomized trials investigating the effects of treatment upon nonspecific low back pain (NSLBP). The authors searched MEDLINE, EMBASE, CINAHL, PyschInfor, and the Cochrane Central Register of Controlled Trials from the earliest record to November 2006. The authors included randomized controlled trials comparing treatments for NSLBP against placebo. Only trials with continuous measures of pain were accepted for review. Studies in which participants demonstrated radicular syndrome, cauda equina syndrome, infection, neoplasm, fracture, inflammatory disease, pregnancy or spinal surgery in the past 12 months were excluded. Also excluded were studies of primary prevention as were trials in which the placebo was a contemporary treatment (e.g. an educational booklet). The authors used the definitions of the American College of Physicians and the American Pain Society to evaluate the magnitude of treatment effects: large > 20 points; moderate 10-20 points; and small < 10 points). A secondary analysis was performed to evaluate the efficacy of treatments in individuals with specific duration of symptoms. In this analysis, the authors combined those trials in which patients experienced pain for greater than 6 weeks, into their definition of CLBP. Two trials, with a total of 57 patients, were found investigating the use of TENS for CLBP as defined by the authors. The authors concluded that there was a moderate effect favoring analgesic efficacy with TENS. However, they also noted that the confidence intervals around these estimates of pain relief were not narrow enough to rule out small effects. McIntosh G, Hall H. Low back pain (chronic). Clinical Evidence . 2008; 10:1116. This is a systematic review that studied the effects of various treatments for chronic low back pain, including non-drug treatments. The authors searched for English language journals of RCTs or systematic reviews that contained trials that were at least single blinded (unless impossible) and included more than 20 subjects (with at least 80% follow up). The search included BMJ Clinical Evidence in May 2007, MEDLINE (1966-May 2007), EMBASE (1980-May 2007), Psychlit (1984-May 2007), The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials 2007, Issue 2 and several websites (NHS Centre for Reviews and Dissemination, Health Technology Assessment, Turning Research into Practice, and NICE). The authors defined chronic low back pain as “pain, muscle tension, or stiffness localized below the costal margin and above the inferior gluteal folds, with or without leg pain (sciatica),” of at least twelve weeks duration. They included studies of people with chronic low back pain with no radiation of discomfort, or studies that included subjects both with and without radiation, if the proportion of people with radiation was less than 50 percent. They excluded studies in which the participants exhibited chronic low back pain with symptoms or signs that suggest a specific underlying condition (e.g. infection, tumor, osteoporosis, rheumatoid arthritis, fracture or inflammation), and studies where the subjects manifested only sciatica and/or pain due to herniated discs. Two systematic reviews and one RCT were included in the review. The authors concluded that the decision to use TENS as an isolated treated for CLBP is poorly defined by the evidence. Poitras S, Brosseau L. Evidence-informed management of chronic low back pain with transcutaneous electrical nerve stimulation, interferential current, electrical muscle stimulation, ultrasound, and thermotherapy. The Spine Journal . 2008;8:226-233. This review evaluates the efficacy of TENS and other modalities for the treatment of nonspecific or rheumatic chronic low back pain that has lasted longer than 12 weeks. The authors searched for French and English RCTs and controlled clinical trials in MEDLINE, EMBASE, Current Contents, CINAHL, and the Cochrane Controlled Trials Register up to August 2006. They also searched the registries of the Cochrane Field of Rehabilitation and Related Therapies and the Cochrane Musculoskeletal Group and the Physiotherapy Evidence Database. Generally, comparisons of two active treatments were excluded as were trials where the patient acted as his/her own control. Trials with subjects that received the placebo, were untreated, or received routine conventional therapeutic approaches were accepted as controls. If concurrent therapies were provided to both investigative and control groups, these trials were also accepted. To a limited extent, cross over trials were included, but only the data prior to the first crossing was analyzed. Studies with differing electrical parameters and treatment frequencies were accepted. In summary, the authors concluded that most of the TENS studies were of poor methodological quality and that variations in TENS parameters and treatment session characteristics made comparisons difficult. The authors also concluded that TENS may have an impact on the reduction of pain in the immediate and short term, but does not appear to have an impact on perceived disability or long term pain. van Middelkoop M. et. al. A systematic review on the effectiveness of physical and rehabilitation interventions for chronic non-specific low back pain. European Spine Journal . 2011;20:19-39. The objective of this systematic review was to determine the effectiveness of various physical and rehabilitation interventions for CLBP. All standard modes of TENS were among the interventions studied. In the investigations included for review, TENS was compared against sham treatment, percutaneous electrical nerve stimulation/acupuncture, and other active treatments. Also conventional TENS was compared to biphasic new wave TENS. The authors searched the Cochrane reviews, MEDLINE, EMBASE, CINAHL, and PEDro up to December 2008 and included articles in English, Dutch, and German. They included RCTs of adults over 18 years of age, with non-specific chronic low back pain that persisted for 12 or more weeks and that evaluated at least one clinically relevant outcome measure (pain, functional status, perceived recovery, or return to work). The authors excluded RCTs where subjects demonstrated specific low back pain due to conditions such as vertebral spinal stenosis, ankylosing spondylitis, scoliosis, and coccydynia. Comparing TENS to sham treatment, the authors concluded that no statistically significant difference on post-treatment pain intensity and disability was found. Further they noted that percutaneous electrical nerve stimulation/acupuncture is more effective than TENS for post treatment and short term pain relief. Between TENS and active treatments, they noted that studies demonstrated there was no statistically significant difference in pain intensity. Finally, one study found no statistically significant differences in the comparison of conventional TENS with biphasic new wave TENS in terms of pain intensity and disability. The authors noted that most of the evidence reviewed was of low quality or was at high risk of bias. Single Study Investigations We found six single study investigations that fit our inclusion criteria. Five were randomized controlled trials (RCTs) and one used a sequential allocation design. The details of these trials are presented in Table 1 and summarized below. Deyo R, Walsh N, Martin D, Schoenfeld L, Ramamurthy S. A Controlled Trial of Transcutaneous Electrical Nerve Stimulation (TENS) and Exercise for Chronic Low Back Pain. New England Journal of Medicine. 1990(a);322(23):1627-1634. The purpose of this study was to examine the efficacy of TENS and stretching exercises alone and in combination for the relief of low back pain. One hundred forty five subjects with CLBP (ages 18-70 years) were randomly assigned to one of 4 groups, including the use of TENS alone and sham TENS. Outcome measures included those related to pain ratings, functional status, physical performance and the use of medical services. Outcomes were recorded after two and four weeks of home therapy and then again two months after the TENS had been discontinued. The authors concluded that for patients with CLBP, treatment with TENS was no more effective than treatment with a placebo and that TENS adds no apparent benefit to exercise alone. Itoh K, Itoh S, Katsumi Y, Kitakoji H. A pilot study on using acupuncture and transcutaneous electrical nerve stimulation to treat chronic non-specific low back pain. Complementary Therapies in Clinical Practice. 2009;15:22-25. The goal of this study was to determine whether acupuncture, TENS, or a combination of acupuncture and TENS was more effective for the treatment of chronic, nonspecific LBP in older patients. A total of 32 patients, ages 60 and above, were randomly allocated to four groups: those treated with acupuncture, TENS, acupuncture and TENS and those in the control group. Each subject received a total of five treatments, provided once per week. Outcomes were measured by the use of a visual analog scale and the Roland – Morris Disability Questionnaire for ten weeks. The authors concluded that their study demonstrated the use of combined acupuncture and TENS to be effective in patients with CLBP as measured by the specified outcomes. Jarzem P, Harvey E, Arcaro N, Kaczorowski J. Transcutaneous Electrical Nerve Stimulation (TENS) for Chronic Low Back Pain. Journal of Musculoskeletal Pain . 2005(a); 13(2): 3-9. The goal of this research was to study the efficacy of TENS for the treatment of CLBP. Three hundred twenty four subjects with CLBP of at least 3 months duration and without leg symptoms were randomized into 4 treatment groups that included 3 different types of TENS and sham TENS. Follow up occurred after 2 and 4 weeks of treatment in the home. Outcome measures included those describing function, motion and depression. The authors concluded that TENS was no better than sham TENS for the treatment of CLBP without leg symptoms. Kofotolis N, Vlachopoulos S, Kellis E. Sequentially allocated clinical trial of rhythmic stabilization exercises and TENS in women with chronic low back pain. Clinical Rehabilitation . 2008; 22:99-111. The purpose of this trial was to investigate the effectiveness of rhythmic stabilization exercises, transcutaneous nerve stimulation and the combination of these therapies upon females (aged 34-46) with chronic low back pain. Ninety-two participants were sequentially allocated into four groups: those receiving rhythmic stabilization exercises; those receiving a combination of rhythmic stabilization exercise and TENS; those receiving only TENS treatments; and those receiving placebo TENS. Treatments and/or training were administered five times per week for four weeks. Outcome measures included data pertaining to functional disability, intensity of pain, as well as trunk range of motion and endurance. Outcomes were recorded after completion of the treatment/training program, and at four and eight weeks after. The authors concluded that combining rhythmic stabilization and TENS was more effective than TENS alone, but not as effective as rhythmic stabilization alone in treating their study population. Shimoji K, Takahashi N, Nishio Y, Koyanagi M, Aida S. Pain Relief by Transcutaneous Electrical Nerve Stimulation With Bidirectional Modulated Sine Waves in Patients With Chronic Back Pain: A Randomized, Double-Blind, Sham-Controlled Study. Neuromodulation: Technology at the Neural Interface . 2007;10(1):42-51. The objective of this study was to compare the effectiveness of TENS using bidirectional modulated sine waves (BMW), to sham TENS in those with CLBP. Outcomes measured were relief of pain and increase in straight leg raising measurements. Twenty one subjects were randomly assigned to two groups: massage plus sham TENS or massage plus TENS using BMWs. Treatments were provided twice weekly for five weeks. The authors stated that their data suggested that there were neither long term effects of TENS by BMW nor interactive effects between massage and TENS. Yokoyama M, Sun X, Oku S, Taga N, Sato K, Mizobuchi S, Takahashi T, Morita K. Comparison of Percutaneous Electrical Nerve Stimulation with Transcutaneous Electrical Nerve Stimulation for Long-Term Pain Relief in Patients with Chronic Low Back Pain. Anesthesia & Analgesia . 2004; 98:1552-6. The purpose of this study was to evaluate the effectiveness of percutaneous electrical nerve stimulation (PENS) treatment of chronic low back pain, using a TENS group as the control. Sixty subjects were randomly assigned to one of three groups: PENS treatment; PENS then TENS treatment; and TENS treatment. Each group was treated two times per week for eight weeks. Assessment of participants’ peak pain levels, physical impairment and analgesic consumption was performed during treatment and one and two months after. The authors concluded that repeated PENS therapy was more effective than repeated TENS therapy in relieving chronic LBP. 4. MEDCAC A Medicare Evidence Development & Coverage Advisory Committee (MEDCAC) meeting was not convened on this issue. 5. Evidence Based Guidelines We searched the National Guideline Clearinghouse ( www.guidelines.gov ) and the Internet more generally for relevant guidelines. Assessment: efficacy of transcutaneous electric nerve stimulation in the treatment of pain in neurologic disorders (an evidence-based review). Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Dubinsky RM, Miyasaki J. Assessment: efficacy of transcutaneous electric nerve stimulation in the treatment of pain in neurologic disorders (an evidence-based review). Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology . 2010 Jan 12;74(2):173-6. Major Recommendations Definitions of the levels of the recommendations (A, B, C, U) and classification of the evidence (I-IV) are provided at the end of the "Major Recommendations" field. Recommendations 1. Transcutaneous electric nerve stimulation (TENS) is not recommended for the treatment of chronic low back pain due to lack of proven efficacy (Level A, 2 Class I studies). 2. TENS should be considered for the treatment of painful diabetic neuropathy (Level B, 2 Class II studies). Level A = Established as effective, ineffective, or harmful (or established as useful/predictive or not useful/predictive) for the given condition in the specified population. (Level A rating requires at least two consistent Class I studies). This guideline was also published as is further reviewed in this memorandum. European Guidelines for the Management of Chronic Non-specific Low Back Pain Airaksinen O, Brox J, Cedraschi C, Hildebrandt J, Klaber-Moffett J, Kovacs F, Mannion A, Reis S, Staal J, Ursin H, and Zanoli G. European Guidelines for the Management of Chronic Non-specific Low Back Pain. 2004. Available at www.backpaineurope.org The writers found “strong evidence that TENS is not more effective than placebo or sham TENS in the treatment of chronic low back pain (Level A)”, therefore TENS was not recommended for the treatment of CLBP For these guidelines Level A (Strong Evidence) was generally consistent with findings for which ≥75 percent of the studies (a systematic review of multiple high quality RCTs) showed a similar result. It should be noted that CLBP was defined in these guidelines as low back pain that lasted at least 12 weeks unless otherwise specified. Philadelphia Panel Evidence-Based Clinical Practice Guidelines on Selected Rehabilitation Interventions for Low Back Pain Albright J, Allman R, Bonfiglio R, Conill A, Dobkin B, Guccione A, Hasson S, Russo R, Shekelle P, Susman J, Brosseau L, Tugwell P, Wells G, Robinson V, Graham I, Shea B, McGowan J, Peterson J, Tousignant M, Poulin L, Corriveau H, Morin M, Pelland L, Laferriére, Casimiro L and Tremblay L. Guidelines on Selected Rehabilitation Interventions Philadelphia Panel Evidence-Based Clinical Practice for Low Back Pain. Journal of the American Physical Therapy Association . 2001;81:1641-1674. The panel concluded that there was “good evidence (Level I) of no clinically important benefit on pain with TENS.” The Panel went on to state their recommendation that there is “poor evidence to include or exclude TENS alone (grade C for pain and function) as an intervention for CLBP.” For these guidelines Level I is evidence from at least 1 properly randomized controlled trial (RCT) and Grade C is poor evidence regarding inclusion or exclusion of an intervention, but recommendations may be made on other grounds. CLBP was defined as low back pain that lasted for >12 weeks. The American College of Physicians and the American Pain Society Chou R, Qaseem A, Snow V, Casey D, Cross T, Shekelle P, and Owens D. Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society. Annals of Internal Medicine . 2007;147:478-491. The authors developed clinical practice guidelines for the diagnosis and treatment of low back pain. In these guidelines, they state that “[t]ranscutaneous electrical nerve stimulation…ha[s] not been proven effective for chronic low back pain.” For these clinical practice guidelines (based on their analysis of systematic reviews), chronic low back pain is defined as back pain that is present for more than 3 months. In the initial public comments, CMS received references to two guidelines that made recommendations on the use of TENS in the treatment of CLBP. One of these guidelines was The Practice Guidelines for Chronic Pain Management: An Updated Report by the American Society of Anesthesiologists Task Force on Chronic Pain Management and the American Society of Regional Anesthesia and Pain Medicine published in April 2010. This guideline states that “TENS should be used as part of a multimodal approach to pain management for patients with chronic back pain and may be used for other pain conditions (e.g. neck and phantom limb pain)." The other guideline was issued by The National Institute for Health and Clinical Excellence (NICE) in 2009 on Low back pain: Early management of persistent non-specific low back pain. The NICE low back pain guidelines recommendation was to “not offer transcutaneous electrical nerve simulation (TENS).” However, the NICE guidelines went on to explain that “(t)hese guidelines have failed to recommend TENS as a treatment, not because of evidence that it does not work, but because there is no evidence that it is effective. The guideline development group did not find any large well-conducted large randomised controlled studies. TENS research should: Establish the most effective stimulation parameters for effective use. Assess pain relief when using TENS, overall daily pain, medication usage and healthcare consulting as outcomes in addition to disability.” It should be noted that the duration of “chronic back pain” and “chronic low back pain” in the NICE management for low back pain guidelines and the chronic pain management guidelines developed by a collaboration of pain management and anesthesia specialty societies respectively, was not specifically defined as CLBP in a similar manner as done for the purposes of this NCD. 6. Professional Society Position Statements We did not find professional society position statements on TENS for CLBP beyond the guidelines cited elsewhere in this decision. 7. Expert Opinion Following the submission of initial public comments, members of the TENS academic and manufacturing community met with CMS to formally present the evidence referenced in their public comments. CMS met with Kathleen Sluka, PT PhD from the University of Iowa, a clinician and academician who has authored and co-authored clinical studies and textbooks on TENS, along with a few of her colleagues. CMS also met with TENS manufacturer RG Medical, representatives from the Neuroscience Device Alliance that represents the largest number of TENS manufacturers in the U.S., and with academician and TENS researcher Melissa Martinson MS PhD from the University of Minnesota. During these meetings CMS was provided an overview of the TENS technology and was presented with evidence from cli