The use of transcutaneous electrical nerve stimulation (TENS) units to treat pain is the best-known form of noninvasive electrical stimulation therapy, but this kind of treatment has many other applications. Electrical stimulation is used to help heal fractures, treat urinary incontinence, and care for pressure ulcers and other nonhealing wounds.

Research indicates the treatment also may prove useful for other conditions. However, getting these treatments approved and reimbursed by third-party payors can be an arduous process.

The initial obstacle is obtaining approval from the US Food and Drug Administration (FDA) to market either a new device or an alternate application for an existing device. The premarket approval process involves putting the product through an often-costly series of extensive clinical trials.

Without approval, the FDA limits what a manufacturer or supplier may claim as a product benefit. Manufacturers of TENS units, for example, are generally prohibited from marketing the units for indications other than pain management. To understand why requires a brief explanation of one aspect of the FDA’s approval process for medical devices.

The fastest and most economical way for a manufacturer to bring a new medical device to market is called a 510(k), after the relevant section of the Food, Drug and Cosmetic Act. However, manufacturers can use the 510(k) only for devices that are “substantially equivalent” to a device on the market before 1976.

If a device is substantially equivalent to a pre-1976 device, it is eligible for limited FDA review. Some kinds of technical improvements will not prevent a device from being considered substantially equivalent to a pre-1976 device. But if there is a significant change in the device, its labeling, or its intended use, then the device will not qualify for a 510(k) and must go through premarket approval.

TENS units were on the market in the United States before 1976, and so it is possible to bring a new TENS unit to market through the 510(k) process. However, pre-1976 TENS devices were labeled only for treatment of pain. Therefore, a new TENS unit will not qualify for a 510(k) if it is marketed for indications other than pain treatment.

Of course, FDA approval is only part of the story. Equally important is whether Medicare and other payors will cover a device. In the case of Medicare, the coverage process can be tortuous and sometimes inscrutable, as illustrated by the history of coverage of electrostimulation for wound care and pelvic floor stimulators.

Practitioners have used electrical stimulation to aid in wound healing for years. In 1994, the Agency for Health Care Policy and Research (AHCPR) issued a clinical practice guideline on the treatment of pressure ulcers that describes electrical stimulation as “the only adjunctive therapy with sufficient supporting evidence to warrant recommendation at this time.” The guideline goes on to recommend that practitioners “consider a course of treatment with electrotherapy for Stage III and IV pressure ulcers that have proved unresponsive to conventional therapy. Electrical stimulation may also be useful for recalcitrant Stage II ulcers.”

In spite of this endorsement by AHCPR, the Centers for Medicare and Medicaid Services (then the Health Care Financing Administration or HCFA) issued a national coverage decision on electrostimulation for wound treatment in 1997, saying it could not cover the therapy because its effectiveness had not been adequately demonstrated.

The American Physical Therapy Association sued HCFA and obtained an injunction prohibiting the administration from enforcing the national coverage decision. HCFA then instructed its regional carriers (DMERCs) that coverage of electrostimulation for wound care should be determined on a case-by-case basis until a new national coverage decision was announced.

After requesting additional input from various parties, HCFA referred the issue to its Medicare Coverage Advisory Committee (MCAC). In October 2000, the Medical and Surgical Procedures Panel of that committee determined that electrical stimulation should be considered more effective than alternative treatments as an adjunctive therapy for chronic nonhealing wounds. The MCAC Executive Committee ratified that decision in February. As of this writing, however, a new national coverage determination has not yet been issued. A CMS representative has advised that a decision is likely within 30 days.

In the case of pelvic floor stimulators, HCFA first issued a national determination of noncoverage in 1994. This determination was reconsidered and reaffirmed in 1996. After being barraged with requests by device manufacturers, HCFA decided to revisit the issue in 1999. First, the agency ordered a technology assessment from the Blue Cross Blue Shield Technology Evaluation Center, a contractor of the Agency for Healthcare Research and Quality (the new title of AHCPR). That assessment concluded that:

1. The available evidence was inadequate to determine the efficacy of pelvic floor electrical stimulation (PFES) for stress incontinence.
2. The available evidence did not suggest that PFES is superior to alternatives for stress incontinence.
3. The evidence for PFES in urge incontinence and postprostatectomy incontinence is sparse.

The issue was then referred to the MCAC, which concluded that:

1. There was insufficient evidence to determine the effectiveness of PFES compared to a placebo for the treatment of incontinence.
2. There was insufficient evidence to determine the effectiveness of PFES compared to alternative nonsurgical techniques.
3. There was insufficient evidence to determine the effectiveness of PFES plus pelvic muscle exercise (PME) compared to PME alone.

The MCAC Executive Committee ratified the MCAC panel recommendations. Nevertheless, a few months later, HCFA issued a program memorandum announcing that PFES devices would be covered for certain patients.

Both the FDA premarket approval process and the Medicare coverage process serve important functions in assuring that unsafe devices are kept off the market and that the Medicare program pays only for effective treatments. However, a manufacturer who tries to get a new treatment approved may be investigating the use of TENS units for headaches by the time the process is complete.

Tim Webster, JD, is an attorney with the Health Care Group of Brown & Fortunato, PC, Amarillo, Tex. He represents HME companies, pharmacies, and other health care providers throughout the United States and Puerto Rico. He can be reached at (806) 345-6347; twebster@bf-law.com.