title: A randomised controlled trial on hypnotherapy for irritable bowel syndrome: design and methodological challenges (the IMAGINE study).
abstract: BACKGROUND
  Irritable Bowel Syndrome (IBS) is a common gastro-intestinal disorder in primary and secondary care, characterised by abdominal pain, discomfort, altered bowel habits and/or symptoms of bloating and distension. In general the efficacy of drug therapies is poor. Hypnotherapy as well as Cognitive Behaviour Therapy and short Psychodynamic Therapy appear to be useful options for patients with refractory IBS in secondary care and are cost-effective, but the evidence is still limited. The IMAGINE-study is therefore designed to assess the overall benefit of hypnotherapy in IBS as well as comparing the efficacy of individual versus group hypnotherapy in treating this condition.
  
  
  METHODS
  The design is a randomised placebo-controlled trial. The study group consists of 354 primary care and secondary care patients (aged 18-65) with IBS (Rome-III criteria). Patients will be randomly allocated to either 6 sessions of individual hypnotherapy, 6 sessions of group hypnotherapy or 6 sessions of educational supportive therapy in a group (placebo), with a follow up of 9 months post treatment for all patients. Ten hospitals and four primary care psychological practices in different parts of The Netherlands will collaborate in this study. The primary efficacy parameter is the responder rate for adequate relief of IBS symptoms. Secondary efficacy parameters are changes in the IBS symptom severity, quality of life, cognitions, psychological complaints, self-efficacy as well as direct and indirect costs of the condition. Hypnotherapy is expected to be more effective than the control therapy, and group hypnotherapy is expected not to be inferior to individual hypnotherapy.
  
  
  CONCLUSIONS
  If hypnotherapy is effective and if there is no difference in efficacy between individual and group hypnotherapy, this group form of treatment could be offered to more IBS patients, at lower costs.
  
  
  BACKGROUND
  ISRCTN: ISRCTN22888906.
authors.affiliation: Julius Centre for Health Sciences and Primary Care, University Medical Centre, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands. c.e.flik@umcutrecht.nl
authors.forename: Carla E
authors.initials: CE
authors.lastname: Flik
authors.forename: Yanda R
authors.initials: YR
authors.lastname: van Rood
authors.forename: Wijnand
authors.initials: W
authors.lastname: Laan
authors.forename: André Jpm
authors.initials: AJ
authors.lastname: Smout
authors.forename: Bas Lam
authors.initials: BL
authors.lastname: Weusten
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Whorwell
authors.forename: Niek J
authors.initials: NJ
authors.lastname: de Wit
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006990:Hypnosis; D043183:Irritable Bowel Syndrome / Q000191:economics / Q000523:psychology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010353:Patient Education as Topic; D018579:Patient Selection; D011788:Quality of Life; D020377:Self Efficacy; D055815:Young Adult