Background: Transitioning care from hospital to outpatient settings is a critical and high-risk period for patients. It also presents substantial challenges for healthcare professionals, who frequently operate in fragmented and uncoordinated systems. Medication safety may be jeopardised, with issues such as medication reconciliation errors, drug-related problems and medication nonadherence leading to potential hospital readmissions. Interprofessional collaborative interventions across care settings have shown promising results by reducing readmissions and enhancing integrated care for patients transitioning from hospital to home. Still, these services are rarely implemented and sustained in standard care. Community pharmacists play a key role in the interprofessional team during hospital discharge; however, their practices and roles in outpatient care at hospital discharge remain insufficiently defined.

Objective: This thesis aimed to explore the perspectives, experiences, and needs of healthcare professionals and polypharmacy patients with long-term conditions during the post-hospitalisation care transition, particularly emphasising outpatient care, interprofessional collaboration, and medication management. Specifically, the ItPaDiab study explored the perspectives of discharged polypharmacy patients regarding their medications and their care journey from hospital to two months after discharge. The FGinterpro study focused on identifying and describing the current state and areas for improvement of interprofessional collaboration in medication management during the transition from hospital to outpatient care. The CPreasoning study aimed to evaluate community pharmacists’ practices and clinical reasoning regarding hospital discharge prescriptions.

Methods: This thesis employed a range of qualitative methodologies to explore care transition and interprofessional and professional practices. The ItPaDiab study focused on patients with type 2 diabetes and at least two long-term conditions discharged home, using four longitudinal semi-structured interviews per participant and self-reported questionnaires over the two-month period following discharge. The FGInterpro study was conducted through interprofessional serial focus groups with patients and healthcare professionals from both hospital and outpatient settings and analysed through the Canadian Interprofessional Health Collaborative (CIHC) Framework. The CPreasoning study used simulations to explore community pharmacists’ practices and retrospective think-aloud methodologies to better understand their clinical reasoning. The clinical reasoning was analysed using the Charlin et al.'s model and the encounter structure through the Calgary-Cambridge model. All studi