Increasing Retention in a Trial by Supporting Basic Psychological Needs for Autonomy, Competence and Relatedness: Developing a Theory‐Informed App‐Based Complex Intervention. - Petersen, Anne Poder; Schmid, Johannes Martin; Hviid‐Vyff, Bjarke; Hoffmann, Hans Jürgen; Finderup, Jeanette (Scandinavian Journal of Caring Sciences, 2026)