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

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.