Damian McNamara

October 22, 2019

A novel, noninvasive, over-the-counter electromagnetic neuromodulation device (ActiPatch, BioElectronics Corp.) appears to deliver long-lasting relief in chronic pain patients. However, at least one pain expert has concerns about the study methodology and interpretation of the results.

Results of a long-term prospective study that included 240 patients who had previously experienced chronic pain relief with the device showed that at 6 months, 97% of the 240 participants sustained 60% reduction in pain. (A short-term study included 682 individuals, and 240 of those people agreed to participate in the longer-term, 6 month study and complete three further assessments.)

Responders also reported functional improvements in sleep quality, physical activity, and overall quality of life, as well as lower consumption of pain medications.

“The vast majority of people who get short-term relief from this medical device get that relief for at least 6 months, their quality of life improves, and it’s a ‘whole different ballgame’ in terms of chronic pain,” lead investigator Richard Staelin, PhD, professor of business administration at The Fuqua School of Business at Duke University in Durham, North Carolina, told Medscape Medical News.

“A doctor can prescribe or recommend this device,” he added. “If it works for 7 days, they’re pretty well guaranteed it will continue to work for at least 6 months.”

The study was published online September 30 in Pain Research and Management.

Electroceuticals and Risk
ActiPatch is sold without a prescription. The unit remains continuously powered for 7 days or as a 30-day device with an on/off switch. It does not require contact with the skin and can be worn outside a bandage or clothing.

The electromagnetic field pulsed shortwave therapy (PSWT) device is one of three main types of neuromodulation systems. Invasive, implanted devices are also on the market, as are semi-invasive systems such as transcutaneous electrical nerve stimulation (TENS) units that require surface electrodes.

“However, these invasive and semi-invasive ‘electroceuticals’ present risks such as skin damage, postsurgical complications and cost, factors which have largely tempered recurring use…for chronic pain management,” the researchers note.

Previous research shows the ActiPatch device was highly effective for short-term relief, but there were no long-term data.

To examine long-term efficacy, the investigators assessed 240 individuals who had chronic pain for an average of 6.5 years.

Arthritis and fibromyalgia were the most common conditions, and the back was the most common location. Participants had an average age of 58 years and 70% were women.

Participants used an average 1.8 pain therapies prior to enrollment. A total of 85% reported taking pain pills, 33% used topical formulations, 27% used heat wraps, 20% participated in physical therapy, and 16% used TENS devices for pain relief.

Surprise Findings
Of the 209 participants who completed the 6-month study, 58% reported mild pain, 36% moderate pain, and the remaining 6% severe pain.

The average baseline VAS score was 8.0. The mean decrease after 7 days of treatment was 5.3 points, or a 65% reduction as measured by the visual analog scale (VAS).

At 6 months, the reduction was 4.9 points vs baseline, or a 60% decrease. The researchers note these findings reflect “the consistency of the treatment effectiveness.”

“These lower levels of pain (and thus large pain reductions) are in stark contrast to the high pain levels these subjects reported having for extended periods of time (average duration of 6.5 years) prior to using the medical device,” the researchers note.

“A couple of things surprised me,” Staelin said. “One of which we have no real explanation for, but women seem to respond more than men.”

Overall, 66% of the women vs 55% of men in this larger population experienced clinically significant decreases in pain after 7 days.

“The other thing I thought was interesting was that some of the people who did not respond greatly to the device but kept using it for longer periods [eventually responded more],” Staelin said.

Pain Reduction
A total 91% of the people who reported severe levels of pain after 7 days of using the device said they were no longer in severe pain at the end of 6 months — 55% reported ‘moderate’ pain and 36% reported a ‘mild’ level of pain.

For example, someone who started the study with a VAS pain level of 10 might report a 7 score after the first week. “That’s clinically significant, but 7 is still a pretty severe pain. After using the device for 6 months, their pain was down more to a level of 4 or 3, which is really pretty tolerable,” Staelin said.

“No one device or no one approach is going to be the panacea for everybody,” he cautioned. “I would just say your probability of success is pretty high when using this device.”

The researchers also found that patients who reported improvement in pain also reported increased quality of life, better sleep, and physical improvements. Furthermore, 28% of the participants said they stopped using any analgesic medications and 16% stopped using other pain management therapies.

The ActiPatch has few adverse events and is relatively inexpensive, Staelin said. “The device costs $10 or $20 for a 7-day trial. It’s not a huge expense. I would think it’s worth a try.”

The lack of a control group in the study is a potential limitation, he noted.

“I would love to do another 6-month study where we do two things,” Staelin said. “One, we use the Central Sensitization Index to measure central sensitization. We can measure that before and after – to confirm the mechanism of action is what we think – that people are less sensitive after 6 months.

“The second thing I would love to have is a control, where we have some people continue with their normal therapy and see if their pain reduces over 6 months. That would rule out that this decrease in pain is due to just time.” It would be easy to use a placebo for this device because you can’t feel it anyway,” he added.

Questions Asked, Answered
Commenting on the findings for Medscape Medical News, Imanuel Lerman, MD, a pain management specialist and associate professor at the VA San Diego Healthcare System in California, noted that the study included no sham control, which makes the findings difficult to interpret.

However, Staelin said he and his colleagues noted the lack of a control group as a potential limitation of the study.

“This arm could have been used to determine the magnitude of any placebo effect or control for other explanations, such as reduction of pain intensity due to resolution of the condition over time, or the increased use of other treatment modalities,” he said.

“It should be noted that in neuromodulation device technology trials, placebo response is consistently 30%,” said Lerman, who is also affiliated with the Center for Stress and Mental Health, Center for Pain Medicine at UC San Diego Health.

“The fact that [the study authors] state there is a 59% pain relief response in these patients is actually only in patients that were selected from a much larger pool. Therefore, I believe this 59% relief report is not technically correct,” Lerman added.

In response, Staelin noted that the researchers acknowledged that the 59% pain relief is applicable mainly to the sample of ‘responders,’ and does not represent the potential pain relief that may occur over 6 months in an ‘intent-to-treat’ approach in the general population.

Lerman also noted that the mechanism by which electromagnetic fields (EMF) may induce neuromodulation at very low power is unclear to him.

“I don’t see any basic science studies that corroborate the authors’ claims that 27 MHz carrier 1 kHz with variable power distribution. To my knowledge, the biological effects — either good or bad — of this EMF waveform are unknown,” he said.

Staelin responded that his team acknowledges the “ambiguity surrounding biological effects associated with EMF, especially since the history of EMF clinical research has been plagued with the lack of a biophysical mechanism of action, as well as any demonstrable physiologic effects.”

He added that although classic bioelectromagnetic theory indicates that radiofrequency fields beyond 10 MHz “are incapable of producing biological effects other than simple heating, previous research shows that when low-power [radio frequency] transmitters are operated adjacent to biological tissue and at maximum output or saturation, modulation of peripheral nerve activity or neuromodulation can occur and indicates that RF EMF electroceuticals can achieve neuromodulation.”

Lerman, who has published multiple studies on neuromodulation, including a review article in June on the evidence supporting spinal cord stimulation for relief of chronic pain, had additional concerns that “pain score data was imputed if it was missing.”

However, Staelin said that while “we acknowledge the reviewer’s concern that imputation of missing pain data can lead to biased outcomes, we discussed in the paper that not all enrolled subjects completed the 6-month study.

“In fact, we took great pains to explore when these subjects dropped out and we compared the distribution of pain scores of this sub-sample to the sample of subjects who completed the study.”

Finally, said Lerman, although the study “may seem to have clinically significant effects, I believe randomized, sham-controlled studies are needed to confirm any findings.”

In response, Staelin said that while more research is always better in determining efficacy, there are “at least two such published studies and multiple registry studies supporting pulsed shortwave therapy efficacy.”

“Since multi-modal approaches are increasingly being preferred to manage chronic pain, we believe that it is important to alerting the pain management community to the availability of a nonpharmacological option,” Staelin added.

Staelin is an investor in, and consultant for, BioElectronics Corporation. His coauthors are paid employees of BioElectronics. Lerman has been a paid consultant for Boston Scientific and received investigator-initiated grants from Boston Scientific and Nevro Corporation.

Pain Res. Manag. Published online September 30, 2019. Full Text

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