title: Psychometric properties of the original Inflammatory Bowel Disease Questionnaire, a Spanish version.
abstract: BACKGROUND
  The Inflammatory Bowel Disease Questionnaire (IBDQ) was developed by Guyatt et al. (1989) and it is the most widely used health-related quality of life instrument for patients with Crohn's disease (CD) and ulcerative colitis (UC). The aim of this study was to assess the psychometric properties of a Spanish version of the original IBDQ by examining the instrument's underlying factor structure, the internal and external validity, and the internal consistency reliability.
  
  
  METHODS
  One hundred and forty seven patients (76 CD, 71 UC) completed the Spanish version of the IBDQ, the Hospital Anxiety and Depression Scale (HADS) and the Temperament and Character Inventory (TCI). Clinical activity was assessed by the CDAI and the Truelove-Witts index.
  
  
  RESULTS
  The confirmatory factor analysis of the IBDQ failed to reproduce the original four-factor structure proposed by Guyatt et al. We found that the Spanish version of the IBDQ consists also of four underlying factors, but the content of each factor and the items included were slightly different. Psychometric testing of the IBDQ revealed that the questionnaire has an acceptable internal and external validity, and a high internal reliability.
  
  
  CONCLUSIONS
  Although confirmatory factor analyses failed to reproduce the original psychometric structure of IBDQ, it seems that the Spanish version of this instrument proved to be valid and reliable for assessing health related quality of life in inflammatory bowel disease patients.
authors.affiliation: Department of Clinical Psychology, Hospital Clínic de Barcelona, Institut Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain. anvidal@clinic.ub.es
authors.forename: Angela
authors.initials: A
authors.lastname: Vidal
authors.forename: Esther
authors.initials: E
authors.lastname: Gómez-Gil
authors.forename: Miquel
authors.initials: M
authors.lastname: Sans
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Portella
authors.forename: Manel
authors.initials: M
authors.lastname: Salamero
authors.forename: Josep M
authors.initials: JM
authors.lastname: Piqué
authors.forename: Julián
authors.initials: J
authors.lastname: Panés
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001007:Anxiety / Q000175:diagnosis / Q000523:psychology; D003863:Depression / Q000175:diagnosis / Q000523:psychology; D004644:Emotions; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000523:psychology; D010555:Personality Inventory; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012919:Social Behavior; D013030:Spain; D011795:Surveys and Questionnaires; D013694:Temperament