A Healthesystems publication

Fall 2015

Thinking Beyond Pain Management with TENS Technology

This well-established technology was developed to suppress pain. But therapy with transcutaneous electrical nerve stimulation (TENS) may also help reduce prescription medication overuse and facilitate physiotherapy.

 Devices that utilize TENS technology have long been used to provide pain relief as an adjunct to other components of an injured worker’s treatment plan, both pharmacologic and non-pharmacologic. However, although TENS is a form of passive therapy, its benefits may go beyond temporary pain management to impact other aspects of a patient’s treatment course. When used properly, TENS may reduce the risk of opioid misuse or slow the rate of opioid dose escalation. It can also help facilitate active treatment modalities such as exercise or physical therapy programs.

THE RELATIONSHIP BETWEEN TENS AND OPIOIDS

The relationship between TENS and opioid therapies is a prime example of why injured worker care must be managed through a comprehensive approach. Although seemingly from two different arms of medical cost management – one therapy falling under the purview of pharmacy benefits, one under durable medical equipment (DME) – they are closely linked and must be considered within the context of a complete treatment plan.

Similar to opioid analgesics, TENS technology is thought to suppress pain signals sent by the central nervous system by activating opioid receptors.1-3 More importantly, it does this without the use of opioids, thereby eliminating not only the potential for addiction and misuse, but a list of potential other adverse events typically associated with opioid medications such as sedation, nausea, dizziness, constipation, physical dependence, and respiratory depression.

The downside of these two therapies working in similar ways means that opioids can negatively impact the effectiveness of TENS therapy. Patients who have already built a tolerance toward opioid analgesics may also exhibit a tolerance for the analgesic effect provided by TENS.3 This may be a contributing factor in studies of TENS technology where there is conflicting evidence on its effectiveness. It also further supports the need to explore non-opioid treatment options early in a claim, when these options have the best chance at driving successful outcomes in a claim.

The upside is that this relationship can be exploited in a beneficial way to combat opioid usage. Just as opioids can impact the effectiveness of TENS, the employment of TENS therapy in an injured worker can have an impact on opioid use.

Healthesystems analyzed a large claims segment that included both TENS and opioid therapies. It was observed that approximately 1 out of 4 patients stopped using opioids after TENS was supplied. While this trend could be the outcome of a combination of factors, including prescribing as well as patient behaviors, it may indicate a positive effect of TENS on opioid usage.4

 

Adjusted survival regression analysis also indicates that TENS is a predictor for reduced risk of opioid dose escalation. Introduction of TENS therapy within a claim increased the number of days showing a morphine equivalent dose (MED) of zero.4

TENS AS PART OF ACTIVE REHABILITATION

Another contributing factor for the lack of consensus regarding the efficacy of TENS is the type of pain for which it is being assessed. Research demonstrates that TENS treatment is more effective at alleviating movement-related pain versus resting pain.5,6 This is good news in the treatment of injured workers, because it means that TENS can serve as an effective adjunct to active treatment modalities designed to improve functional outcomes, such as a physical therapy or exercise regimens.

The role of TENS in rehabilitation is supported by a recent placebo-controlled trial of more than 300 patients. The trial evaluated the efficacy of TENS as part of rehabilitation following total knee arthroplasty. Patients receiving TENS therapy experienced less range-of-motion pain during activities that included active knee extension and fast walking.6 Since the goal of treatment in workers’ compensation is improved function, the ability of TENS technology to manage pain while employing active modalities underscores its importance in overall treatment. That it can accomplish this without the use of opioids, with little-to-no side effects, and for a low cost only enhances its benefits.

 EFFECTIVE APPLICATION AND MANAGEMENT OF TENS THERAPY

As mentioned previously, there has been a lack of consensus among studies measuring the effectiveness of TENS therapy. While some suggest that it is primarily effective in nerve-related pain such as fibromyalgia or diabetic neuropathy, other studies and meta-analyses demonstrate efficacy in chronic musculoskeletal pain.7 Patients may also build up a tolerance to the effect of TENS therapy decreasing its effectiveness over the long term, similar to the way in which opioid tolerance is developed. It has also been argued that there is a placebo effect associated with TENS treatment that contributes to perceived pain relief.

Initial Prescribing: While it is true that effectiveness varies among patients and is dependent on a number of variables, there are a significant number of patients who receive valuable pain reduction benefits from TENS technology. The trick, as with any treatment, is to ensure appropriate prescribing for the right patient.

Product Selection: There are many brands and models of TENS units available ranging from inexpensive (e.g., 20 USD) to very expensive (e.g., 1,000 USD), all of which are based upon the same technology. Just like drug medications where there are “generic” and “brand” versions of TENS devices, selection should be guided by the same factors of clinical appropriateness and cost. Often, a device can be purchased for an amount equal to or less than the cost of a single month’s rental. A DME program that provides transparency can help payers avoid inflated prices for what should be, when managed appropriately, a highly cost-effective treatment approach – not only in terms of direct cost, but for the potential it has to reduce risk of opioid dose escalation and the financial implications of high MED within a claim.

Continued Management: Monitoring patient benefit and electrotherapy supplies utilization is an important component of managing TENS therapy throughout the care continuum, both from the patient-care and cost-savings perspectives. It is important to validate that an injured worker patient is continuing to use and benefit from TENS therapy. Although many TENS devices themselves are inexpensive, associated supplies can contribute to more than 90% of overall TENS-related costs in long-term use claims. These costs can add up unnecessarily when patients stop using the device, but continue to receive supplies. Ongoing, prospective management of long-term electrotherapy significantly reduces wasted spend and ensures the patient is receiving beneficial care.

Although TENS technology has existed for decades, new products continue to be developed. Last year, the U.S. Food and Drug Administration (FDA) approved Quell, an over-the-counter device for the 24-hour treatment of neuropathic pain. Another upcoming product is the Cur modulated TENS system, which has an anticipated FDA approval of November 2015. This device is designed to stick directly to skin like a bandage, and like the Quell, does not contain any wires or require electrode placement. While these new devices have some features that may appeal to consumers, such as no lead wires or the ability to wear during sleep - there is no evidence to date that they provide any improvement in outcomes compared with standard TENS units. The same clinical benefits can be achieved with generic units at a fraction of the price.

 In general, adjunctive TENS is a valuable part of an injured worker's treatment plan. It is inexpensive (much more so than other electronic modalities such as Interferential Frequency Current (IFC) and H-wave), and has very little risk of complications or side effects. The use of TENS has been shown to impact opioid use and help facilitate functional improvement be reducing the amount of pain experienced by patients during their active component of therapy. It provides similar benefits to opioid medication without the association rick. The inclusion of TENS technology must be considered not based only on its immediate, short-term benefits, but in a comprehensive context that incoudes other non-pharmacologic as well as pharmacologic components of therapy. 

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SOURCES

1 -Sluka KA, Deacon M, Stibal A et al. Spinal blockade of opioid receptors prevents the analgesia produced by TENS in arthritic rats. J Pharmacol Exp Ther. 1999;289:840-6.
2 -Kalra A, Urban MO, Sluka KA. Blockade of opioid receptors in rostral ventral medulla prevents antihyperalgesia produced by transcutaneous electrical nerve stimulation (TENS). J Pharmacol Exp Ther. 2001;298:257-63.
3 -Leonard G, Goffaux P, Marchand S. Deciphering the role of endogenous opioids in high-frequency TENS using low and high doses of naloxone. Pain. 2010;151:215-9.
4 -Healthesystems data.
5 -Rakel B, Frantz R. Effectiveness of transcutaneous electrical nerve stimulation on postoperative pain with movement. J Pain. 2003;4:455–464
6 -Rakel BA, Zimmerman MB, Geasland K, et al. Transcutaneous electrical nerve stimulation for the control of pain during rehabilitation after total knee arthroplasty: A randomized, blinded, placebo-controlled trial. Pain. 2014;155:2599- 611.
7 -Johnson M, Martinson M. Efficacy of electrical nerve stimulation for chronic musculoskeletal pain: a meta-analysis of randomized controlled trials. Pain. 2007;130:157-65
8 -Sluka K, Bjordal JM, Marchand S, et al. What makes transcutaneous electrical nerve stimulation work? Making sense of the mixed results in the clinical literature. Phys Ther. 2013;93:1397-402.
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