Development and psychometric evaluation of TEXP-Q : a questionnaire measuring transition and transfer experiences in emerging adults with type 1 diabetes.

BACKGROUND: During transition to adulthood and transfer to adult healthcare, emerging adults with chronic conditions are at risk of deteriorating disease control, well-being, and acute, as well as long-term complications. Despite an increasing call for person-centred healthcare services attuned to young peoples' needs, few validated instruments exist pinpointing adolescents' and emerging adults' experiences of preparation for transition and transfer. Thus, the overarching purpose of this study was to develop a person-centred, clinically applicable instrument (Transitional care EXPeriences Questionnaire, TEXP-Q) adjustable to different chronic conditions, although the focus in the present study was Type 1 Diabetes. The specific aim was, therefore, to describe the development and psychometric evaluation of TEXP-Q in emerging adults with Type 1 Diabetes. METHODS: Initial development of the TEXP-Q was inspired by existing research. Items were formulated in accordance with consensus recommendations for developing patient-reported measures, and extra consideration was taken to ensure person-centredness. Psychometric evaluation comprised two phases: In phase I, data from cognitive interviews, content validity indexing, and judgement of an expert panel provided information on face and content validity. In phase II, data from a cross-sectional study conducted at eight adult diabetes outpatient clinics in Sweden (n = 163) allowed for explorative factor analysis (EFA), as well as calculation of content validity, reliability and responsiveness. RESULTS: Combining results from cognitive interviews, content validity index values and expert panel judgement, a test version of TEXP-Q was developed, the content and face validity of which were considered good. This version consisted of 17 items answered on a five-point Likert scale, and three open-ended questions answered in free text. During EFA, four items were removed, and a three-factor solution was recognised as most adequate, ac