title: Stress as a Trigger for Relapses in IBD: A Case-Crossover Study.
abstract: BACKGROUND
  It is important to identify factors that influence the risk of relapses in inflammatory bowel disease. Few studies have been conducted and with limited methodology. This prospective case-crossover study, aims to examine whether perceived stress has a short-term acute effect, namely whether it acts as a trigger, on the risk of relapse in inflammatory bowel disease.
  
  
  METHODS
  Sixty patients with inflammatory bowel disease and in remission were included. The case-crossover design was employed, which is an epidemiological design developed to study triggers for acute events and diseases. To collect information regarding symptoms and potential trigger factors, such as perceived stress, a structured diary was constructed. The participants were instructed to fill in the diary daily during six months. Fifty patients completed the study.
  
  
  RESULTS
  The analysis showed an effect for high level of perceived stress. Being exposed to "quite a lot" of stress, yield an increase in risk for relapse during the forthcoming day (OR = 4.8, 95% CI 1.09 - 21.10). No statistically increased risk for lower levels of perceived stress was found, although elevated effect estimates were found for "some" stress.
  
  
  CONCLUSIONS
  This study supports earlier findings regarding perceived stress as an important factor in triggering relapses in IBD. However, this is the first case-crossover study performed to explore the trigger risk of stress in this population. Further investigations with larger patient samples are needed to confirm the findings.
authors: Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, Sweden.
authors: Susanna
authors: S
authors: Jaghult
authors: Red Cross University, Sweden; Karolinska Institute, Department of Clinical Neuroscience, Division of Insurance Medicine, Sweden; University of Stockholm, Stress Research Institute, Sweden.
authors: Fredrik
authors: F
authors: Saboonchi
authors: Karolinska Institute, Department of Public Health Sciences, Division of Public Health Epidemiology, Sweden.
authors: Jette
authors: J
authors: Moller
authors: Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, Sweden; Sophiahemmet University College, Sweden.
authors: Unn-Britt
authors: UB
authors: Johansson
authors: Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, Sweden.
authors: Regina
authors: R
authors: Wredling
authors: Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, Sweden.
authors: Marjo
authors: M
authors: Kapraali
keywords: Case-crossover design; Inflammatory bowel disease; Stress; Trigger factors