Improving Transition Care for Adolescents and Young Adults with Type 1 Diabetes: A Randomized Controlled Trial of SHIFT2 - PROJECT SUMMARY / ABSTRACT For youth with type 1 diabetes (T1D), the transition into young adulthood is a high-risk period for deteriorations in glycemic control. T1D self-management, a key driver of glycemic control, is complicated by the transitional nature of this developmental period, which is associated with changes in multiple domains (i.e., biological, social, and environmental). Evidenced-based transition preparation interventions are needed prior to initiating adult healthcare to improve T1D self-management and glycemic control and increase transition readiness; however, evidence from rigorous trials is limited. To address this gap, we developed and conducted a single-arm pilot of SHIFT, a multisystem transition preparation intervention. Preliminary data from this pilot informed the current application, which proposes to conduct a randomized controlled trial (RCT) of a clinic-based transition preparation intervention (SHIFT2) for adolescents and young adults (AYAs) with T1D. Fifty AYAs (16-22 years) and a parent will be randomized to either: 1) a 6-month multisystem transition preparation program (SHIFT2), or 2) enhanced treatment as usual (TAU+). TAU+ includes usual T1D care, provider training, and standard patient education, matched to the intervention contact schedule. SHIFT2 will employ a hybrid delivery mode for intervention visits using clinic staff (Certified Diabetes Care and Education Specialists [CDCES]) and hospital- based technology platforms (e.g., virtual visits, patient portal). AYAs will receive evidence-based content across 3 domains: psychoeducation/skill building, behavioral self-management, and provider communication. Parents will receive psychoeducation and training in developmentally appropriate parenting strategies to support their AYA in increasing independent self-management and preparing for transition. Providers will receive a video module that highlights their role preparing AYAs for transition and provides evidence-based, practical tips to enhance communication with AYAs. In order to understand key stakeholders’ experiences regarding transitioning to adult care, qualitative interviews with a subset of AYAs who transitioned to adult care and their parents (n=20 AYA-parent dyads) and with providers (n=10 endocrinology providers and CDCES), will be conducted to inform further protocol refinement for future studies. This application has compelling scientific and clinical significance. It improves upon prior research via use of a rigorous RCT design, evidence-based intervention components within a multisystem framework, and objective assessment of the primary outcome (HbA1c). Findings will advance science and inform clinical recommendations regarding optimal strategies to promote independent T1D self-management in AYAs prior to transitioning to adult care. .