Copen-SCALE: scaling-up an effective intervention to childcare institutions in Copenhagen – a stepped wedge type II hybrid effectiveness-implementation trial. A study protocol. - Stilling, Mia Nyvang; Lindberg, Line; Tuck, Laura Downs; Sørensen, Ole Henning; Holtermann, Andreas; Rasmussen, Charlotte Diana Nørregaard (BMC Public Health, 2025)