Multidomain Behavioral Change Digital Coaching for Chronic Disease Management in Patients With Type 2 Diabetes: Framework Development and Preliminary Evaluation - Konstantina Kostopoulou; Danae Lekka; Aristodemos Pnevmatikakis; Nelina Angelova; Panagiotis Stafylas; Stefanos Tamouridis; Alexandra Bargiota; Sofoklis Kyriazakos (JMIR Formative Research)