title: The role of psychological stress in inflammatory bowel disease: quality assessment of methods of 18 prospective studies and suggestions for future research.
abstract: BACKGROUND
  Enquiries among patients on the one hand and experimental and observational studies on the other suggest an influence of stress on inflammatory bowel diseases (IBD). However, since this influence remains hypothetical, further research is essential. We aimed to devise recommendations for future investigations in IBD by means of scrutinizing previously applied methodology.
  
  
  METHODS
  We critically reviewed prospective clinical studies on the effect of psychological stress on IBD. Eligible studies were searched by means of the PubMed electronic library and through checking the bibliographies of located sources.
  
  
  RESULTS
  We identified 20 publications resulting from 18 different studies. Sample sizes ranged between 10 and 155 participants. Study designs in terms of patient assessment, control variables, and applied psychometric instruments varied substantially across studies. Methodological strengths and weaknesses were irregularly dispersed. Thirteen studies reported significant relationships between stress and adverse outcomes.
  
  
  CONCLUSIONS
  Study designs, including accuracy of outcome assessment and repeated sampling of outcomes (i.e. symptoms, clinical, and endoscopic), depended upon conditions like sample size, participants' compliance, and available resources. Meeting additional criteria of sound methodology, like taking into account covariates of the disease and its course, is strongly recommended to possibly improve study designs in future IBD research.
authors: Department of General Internal Medicine, Division of Psychosomatic Medicine, Bern University Hospital, University of Bern, Switzerland. rafael.camara@insel.ch
authors: Rafael J A
authors: RJ
authors: Cámara
authors: Roger
authors: R
authors: Ziegler
authors: Stefan
authors: S
authors: Begré
authors: Alain M
authors: AM
authors: Schoepfer
authors: Roland
authors: R
authors: von Känel
mesh_terms: D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000209:etiology* / Q000523:psychology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012107:Research Design; D013315:Stress, Psychological / Q000150:complications* / Q000473:pathology*