Protocol of a multicentre randomised trial
Six versus twelve sessions of hypnotherapy for irritable bowel syndrome:
A randomised, controlled, single blind non-inferiority trial
Background: Gut focused hypnotherapy relieves the symptoms of IBS in approximately two thirds of patients with the benefit sustained over many years. Despite being endorsed by the National Institute for Care and Health Excellence (NICE), the provision of hypnotherapy has not been widely adopted probably because it is time consuming (twelve sessions), costly to provide and there are no set protocols. Therefore, the benefits of hypnotherapy are not generally available resulting in patients seeking treatment privately from therapists without the necessary qualifications. Aims: This study aimed to compare six sessions of structured versus twelve sessions of conventionally delivered gut focused hypnotherapy in a randomised single blind controlled non-inferiority (equivalence) trial. Methods: Patients consenting to participate were randomised to receive either conventional or streamlined gut focused hypnosis. At baseline (Table 1), they completed the IBS Symptom Severity Score (IBS SSS), the Non Colonic Symptom Score, a Quality of Life Score, the Hospital Anxiety and Depression Score and the EQ5D health state score (score of 1 equals full health). All these measures were repeated at the end of treatment. A responder was defined as a 50 point or more reduction in the IBS SSS (the primary outcome). The proportion of patients experiencing a 30% or more reduction in their pain score was also calculated (FDA recommendation). In addition, the proportion of patients achieving the more demanding outcomes of a 100 or a 150 point reduction in the IBS SSS was calculated. Results: 498 patients were randomised, of whom 448 (92%) had a baseline assessment and attended at least one session of hypnotherapy. 222 were allocated to conventional and 226 to streamlined hypnotherapy. In the intent to treat analysis, the response rate for the primary outcome was 74.0% for conventional and 79.1% for streamlined hypnotherapy (mean difference of 5.1%; 95% CI (- 3.1%,13.3%);p=0.22). With regard to the more demanding endpoints of a reduction in the IBS SSS of 100 points or more and 150 points or more, the figures were 54.7% versus 59.2% (p=0.58) and 37.6% versus 40.7% (p=0.53) for conventional compared to streamlined respectively. 57.0% of conventionally treated and 63.4% of streamlined treated patients achieved a 30% or more reduction in abdominal pain score (p=0.21). There were no significant differences in response between the two groups with respect to IBS severity, sex or change in anxiety or depression scores. The drop out rate was 15% in the conventional group compared to only 9% in the streamlined group (P=0.04). Table 2 details the remaining results. Conclusion: Maximum improvement in IBS symptoms is achieved with six sessions of hypnotherapy and effectiveness is not further enhanced by offering twelve sessions. Furthermore, the dropout rate rises with more sessions.