Fig. 1

Conceptual model. Conceptual design of the intervention. Intervention components with a number (#) are taken from Knittle [70]. For example, #39 corresponds to the intervention component number 39,“Credible Source” in Knittle, Heino [70]. The remaining intervention components are derived from Vorganti et al. [98], Kramer et al. [73], and De Vecchi et al. [99]