Background: Hypnotherapy for Irritable Bowel Syndrome (IBS) has been primarily used in patients with refractory symptoms in specialised departments and delivered on an individual basis. The IMAGINE study compares the effectiveness of hypnotherapy for IBS-patients referred from primary and secondary care, delivered in either a group or an individual setting.
Methods/Design: In a multi-centre randomised placebo-controlled trial, 354 primary and secondary care patients with IBS, age 18-65, were randomly allocated to either six sessions of individual hypnotherapy, group hypnotherapy or educational supportive therapy in a group (control group). Randomisation was carried out by means of a computer-based, six-block random number table’s procedure performed by staff not involved in the treatment. Outcome measures were assessed prior to treatment, immediately after treatment (at three months) and at 12 months (nine months after finishing the treatment). Primary outcome parameter was the responder rate for adequate relief (AR) of IBS symptoms. Trial register: Current Controlled Trials. Registration number: ISRCTN22888906
Results: At three months, 40.2% of patients in the individual hypnotherapy group, 34.1% in the group hypnotherapy group, and 17.1% in the educational supportive group were responders on the primary outcome, the AR questionnaire. At 12 months the figures were 41.8%, 50.0%, and 22.6% respectively. In the intention to treat analysis (ITT), hypnotherapy was more effective than EST, both at three months (OR 2.9, 95%CI 1.2 to 7.4, p=0.02) and at 12 months (OR 2.8, 95%CI 1.2 to 6.7, p=0.02). Per protocol analysis did not show significant differences between individual and group hypnotherapy. The reported serious unexpected serious adverse reactions were judged by the Medical Ethics committee as not being related to the therapy.
Conclusion: Both individual and group hypnotherapy resulted in significantly greater adequate relief of symptoms compared to control treatment. Furthermore, group therapy was not significantly inferior to individual treatment, which would allow many more patients to be treated for the same cost.