title: Validation of the IMPACT-III quality of life questionnaire in Swiss children with inflammatory bowel disease.
abstract: OBJECTIVE
  Inflammatory bowel disease (IBD) frequently manifests during childhood and adolescence. For providing and understanding a comprehensive picture of a patients' health status, health-related quality of life (HRQoL) instruments are an essential complement to clinical symptoms and functional limitations. Currently, the IMPACT-III questionnaire is one of the most frequently used disease-specific HRQoL instrument among patients with IBD. However, there is a lack of studies examining the validation and reliability of this instrument.
  
  
  METHODS
  146 paediatric IBD patients from the multicenter Swiss IBD paediatric cohort study database were included in the study. Medical and laboratory data were extracted from the hospital records. HRQoL data were assessed by means of standardized questionnaires filled out by the patients in a face-to-face interview.
  
  
  RESULTS
  The original six IMPACT-III domain scales could not be replicated in the current sample. A principal component analysis with the extraction of four factor scores revealed the most robust solution. The four factors indicated good internal reliability (Cronbach's alpha=.64-.86), good concurrent validity measured by correlations with the generic KIDSCREEN-27 scales and excellent discriminant validity for the dimension of physical functioning measured by HRQoL differences for active and inactive severity groups (p<.001, d=1.04).
  
  
  CONCLUSIONS
  This study with Swiss children with IBD indicates good validity and reliability for the IMPACT-III questionnaire. However, our findings suggest a slightly different factor structure than originally proposed. The IMPACT-III questionnaire can be recommended for its use in clinical practice. The factor structure should be further examined in other samples.
authors.affiliation: Department of Psychosomatics and Psychiatry, University Children's Hospital, Zurich, Switzerland.
authors.forename: Helene
authors.initials: H
authors.lastname: Werner
authors.affiliation: Department of Psychosomatics and Psychiatry, University Children's Hospital, Zurich, Switzerland; Children's Research Center, University Children's Hospital, Zurich, Switzerland.
authors.forename: Markus A
authors.initials: MA
authors.lastname: Landolt
authors.affiliation: Divison of Gastroenterology and Nutrition, University Children's Hospital, Zurich, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Buehr
authors.affiliation: Divison of Gastroenterology and Nutrition, University Children's Hospital, Zurich, Switzerland.
authors.forename: Rebekka
authors.initials: R
authors.lastname: Koller
authors.affiliation: Division of Gastroenterology, University Children's Hospital, Lausanne, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Nydegger
authors.affiliation: Division of Gastroenterology, Children's Hospital, Lucerne, Switzerland.
authors.forename: Johannes
authors.initials: J
authors.lastname: Spalinger
authors.affiliation: Division of Gastroenterology, Children's Hospital, Winterthur, Switzerland.
authors.forename: Klaas
authors.initials: K
authors.lastname: Heyland
authors.affiliation: Division of Gastroenterology, University Children's Hospital, Berne, Switzerland.
authors.forename: Susanne
authors.initials: S
authors.lastname: Schibli
authors.affiliation: Divison of Gastroenterology and Nutrition, University Children's Hospital, Zurich, Switzerland; Children's Research Center, University Children's Hospital, Zurich, Switzerland. Electronic address: Christian.Braegger@kispi.uzh.ch.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Braegger
mesh_terms: D000293:Adolescent; D002648:Child; D003093:Colitis, Ulcerative / Q000523:psychology*; D003424:Crohn Disease / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013557:Switzerland
keywords: Children; Inflammatory bowel disease; Quality of life; Validation