Ethical and coordinative challenges in setting up a national cohort study during the COVID-19 pandemic in Germany. - Tilch K; Pütz SM; Appel K; Kraus M; Lorenz-Depiereux B; Pilgram L; Anton G; Berger S; Geisler R; Haas K; Illig T; Krefting D; et al. (BMC medical ethics, 2023)