What are the risk factors for avoidable transitions in the last year of life?: a qualitative exploration of professionals’ perspectives for improving care in Germany - Kasdorf, Alina; Dust, Gloria; Vennedey, Vera; Rietz, Christian; Polidori, Maria Cristina; Voltz, Raymond; Strupp, Julia; Ansmann, Lena (BMC health services research, 2021)