Note: This advice is given by the CAP Executive about non-broadcast advertising. It does not constitute legal advice. It does not bind CAP, CAP advisory panels or the Advertising Standards Authority.
Every now and then the Copy Advice team is asked what claims are acceptable for Transcutaneous Electrical Nerve Stimulation (TENS) machines. In general, these devices claim to deliver pain relief by stimulating the nervous system to block the pain ‘gateway’ to the brain. They do that by delivering small electrical pulses via electrodes placed on the skin.
In the past, CAP has allowed marketers to make claims for the temporary relief of minor aches and pains. Marketers were advised not to make pain relief claims for chronic or serious conditions or imply that the pain relief was guaranteed or would work for everyone. But that position could change; as far as CAP understands, the evidence for TENS seems to be inconclusive, in terms of both how effective they are and the conditions it can treat. That some people might benefit from the placebo effect is clearly not a good enough basis on which to make pain relief claims. And the popularity of TENS machines and their use by pain consultants and in hospitals is not proof that it works. Furthermore, TENS machines do not all use the same pulse rates or frequencies and that could affect their efficacy. It is therefore possible that some devices might be demonstrably more effective than others.
In 2004, the ASA upheld a challenge about the efficacy of a TENS type of device (Tower Health Ltd, 19 May 2004). The advertiser was unable or unwilling to provide evidence that its product could relieve pain and was told not to refer to serious medical conditions such as arthritis, rheumatism or osteoporosis.
Marketers who have wanted to go further than the accepted position of pain relief for minor aches and pains have sent the Copy Advice team numerous studies. Marketers should remember that trials done on animals, on dorsal horn cells or in-vitro are unlikely to be acceptable (Rule 12.1). Similarly, although of some background interest, trials conducted on healthy subjects are likely to be considered irrelevant if marketers want to make pain-relief claims but do not have controlled trials conducted on pain sufferers.
When assessing the data, the Copy Advice team have considered resources such as meta-analyses by Bandolier. In its assessment, Bandolier has concluded that not enough high quality evidence exists to show that TENS is effective in the relief of post-operative pain, labour pain, or chronic pain. More information can be obtained from http://www.medicine.ox.ac.uk/bandolier/. If they want to make claims beyond those of minor aches and pains, marketers should be prepared to provide robust clinical trials that avoid bias and the random play of chance and whose design in terms of dose or intervention, duration or measured outcomes meet acceptable criteria. Marketers might want to read the CAP Help Note on Substantiation.
See also entries on ‘Pain’ and ‘Medical Devices’.
Last modified : 26 July 2010