Efficacy of a combination of hypnosis and transcutaneous electrical nerve stimulation for chronic non-cancer pain: A randomized controlled trial

Background Chronic non-cancer pain, which persists for at least three months, seriously affects quality of life. Chronic non-cancer pain patients are usually managed by a multidisciplinary team using pharmacological and non-pharmacological strategies. Nurses perform transcutaneous electrical nerve stimulation (TENS) and hypnosis, which are widely used in France for the treatment of chronic pain in pain departments. Objective To assess pain relief at three months, comparing a simultaneous combination of hypnosis and TENS (intervention) with TENS alone (control). Design Randomized controlled trial. Methods Patients aged 18-80 years, suffering from chronic peripheral neuropathic and/or nociceptive non-cancer pain were included (September 2013 to May 2017) and followed for six months. The primary outcome was the pain intensity difference (by visual analog scale score) between month 3 and baseline. The secondary outcomes, assessed at months 3 and 6, were SF36 score, analgesics consumption and number of TENS sessions performed at home (last seven days). Results Seventy-two patients were included, suffering from a combination of chronic non-cancer nociceptive and neuropathic pain, with a mean pain intensity of about sixty out of a hundred. The results show an important pain reduction (forty percent) in both groups at 3 months. No significant difference was observed between the control and intervention groups. Similarly, SF36 score, change in analgesic intake and patient compliance did not differ significantly between groups. Conclusions This is the first randomized controlled study showing a decrease of pain intensity and a high level of compliance with transcutaneous electrical nerve stimulation alone or associated to hypnosis. The combination does not seem to be more efficient than transcutaneous electrical nerve stimulation alone. Chronic non-cancer pain remains a major issue and a substantial proportion of patients do not appear to benefit from interventions. Impact This study increases our understanding of the combination of two non-pharmacological methods in chronic non-cancer pain patients. The combination of the two non-pharmacological strategies did not appear to be more efficient than one alone. Further research on non-pharmacological treatments targeting to patient's characteristics are needed to find appropriate strategies in patients with complex multidimensional pain conditions.