Development and content validation of the Healthcare Transition Outcomes Inventory for young adults with type 1 diabetes

BACKGROUND: The literature on the specification and measurement of the outcomes of the healthcare transition from pediatric to adult centered-care is scarce and methodologically weak. To address these gaps, we conducted a series of studies to develop a multidimensional, multi-informant (young adults, parents, and healthcare providers) measure of healthcare transition outcomes for young adults with type 1 diabetes (T1D), the Healthcare Transition Outcomes Inventory (HCTOI). The current study describes the development and refinement of the HCTOI item pool. METHODS: Following Patient Reported Outcomes Measurement Information System (PROMIS) standards, the research team conducted qualitative interviews to define six content domains of healthcare transition outcomes from the perspectives of multiple stakeholders, developed an initial item pool of the HCTOI based on the six domains, analyzed expert item ratings and feedback for content validation, and conducted cognitive interviews with informants (patients, parents, and healthcare providers) for further item pool refinement. RESULTS: Qualitative findings revealed six healthcare transition outcome domains: 1) Biomedical markers of T1D control; 2) Navigation of a new health care system; 3) Possession of T1D self-management skills and knowledge; 4) Integration of T1D care into emerging adult roles; 5) Balance of parental involvement with autonomy; and 6) Attainment of T1D “ownership.” An initial pool of 88 items focused on the extent to which a young adult with T1D is successful on each of the six domains. Experts rated all content domains and all but six items as relevant. In addition to suggesting additional items, experts were concerned about the length of the measure, response burden, and whether every informant type would have sufficient knowledge to rate items in particular content domains. Cognitive interviews resulted in retaining all six content domains, but dropping some items and yielded fewer items for the healthcare provider version (47 items versus 54 items for the young adult- and parent-versions). CONCLUSIONS: Expert review and cognitive interviews confirmed that all six domains of HCT outcomes were relevant and both procedures resulted in retaining a sufficient number of clear and representative items for each content domain. The HCTOI represents the first multi-informant, rigorously developed item pool that comprehensively measures the multiple components of the transition from pediatric to adult specialty healthcare.