title: Illness Identity in Adolescents and Emerging Adults With Type 1 Diabetes: Introducing the Illness Identity Questionnaire.
abstract: The current study examined the utility of a new self-report questionnaire, the Illness Identity Questionnaire (IIQ), which assesses the concept of illness identity, or the degree to which type 1 diabetes is integrated into one's identity. Four illness identity dimensions (engulfment, rejection, acceptance, and enrichment) were validated in adolescents and emerging adults with type 1 diabetes. Associations with psychological and diabetes-specific functioning were assessed.
  
  
  
  A sample of 575 adolescents and emerging adults (14-25 years of age) with type 1 diabetes completed questionnaires on illness identity, psychological functioning, diabetes-related problems, and treatment adherence. Physicians were contacted to collect HbA1c values from patients' medical records. Confirmatory factor analysis (CFA) was conducted to validate the IIQ. Path analysis with structural equation modeling was used to examine associations between illness identity and psychological and diabetes-specific functioning.
  
  
  
  CFA indicated that the IIQ has a clear factor structure, meaningfully differentiating four illness identity dimensions. Rejection was related to worse treatment adherence and higher HbA1c values. Engulfment was related to less adaptive psychological functioning and more diabetes-related problems. Acceptance was related to more adaptive psychological functioning, fewer diabetes-related problems, and better treatment adherence. Enrichment was related to more adaptive psychological functioning.
  
  
  
  The present findings underscore the importance of the concept of illness identity. A valid and reliable measure, the IIQ, is introduced to measure four illness identity dimensions in individuals with type 1 diabetes. These four illness identity dimensions were uniquely related to psychological and diabetes-specific functioning.
authors.affiliation: KU Leuven, Leuven, Belgium leen.oris@ppw.kuleuven.be.
authors.forename: Leen
authors.initials: L
authors.lastname: Oris
authors.affiliation: KU Leuven, Leuven, Belgium.
authors.forename: Jessica
authors.initials: J
authors.lastname: Rassart
authors.affiliation: KU Leuven, Leuven, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Prikken
authors.affiliation: KU Leuven, Leuven, Belgium.
authors.forename: Margaux
authors.initials: M
authors.lastname: Verschueren
authors.affiliation: Ghent University, Ghent, Belgium.
authors.forename: Liesbet
authors.initials: L
authors.lastname: Goubert
authors.affiliation: KU Leuven, Leuven, Belgium University of Gothenburg, Gothenburg, Sweden.
authors.forename: Philip
authors.initials: P
authors.lastname: Moons
authors.affiliation: The University of Utah, Salt Lake City, UT.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Berg
authors.affiliation: Free University of Brussels, Brussels, Belgium.
authors.forename: Ilse
authors.initials: I
authors.lastname: Weets
authors.affiliation: KU Leuven, Leuven, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Luyckx
mesh_terms: D000293:Adolescent; D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000523:psychology* / Q000628:therapy; D059026:Diagnostic Self Evaluation; D005260:Female; D006801:Humans; D055809:Illness Behavior / Q000502:physiology; D008297:Male; D010349:Patient Compliance / Q000523:psychology; D010549:Personal Satisfaction; D010555:Personality Inventory; D000297:Psychology, Adolescent; D015203:Reproducibility of Results; D012648:Self Care / Q000523:psychology; D012649:Self Concept; D057566:Self Report / Q000592:standards*; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult