ELIPSE-II represents a single-blind randomized controlled parallel-group clinical trial. In total, 160 children, \<6 years of age with exposure to second-hand smoke at home will be included. Children will be recruited at the children's university hospital and in private practices in Bern, and randomly (1:1) assigned to a control and intervention group.
All participants receive treatment-as-usual (TAU), parents of participants in the intervention group additionally receive a smartphone application (lifestyle app) for 20 weeks. The app aims to promote healthy behavior through cognitive-behavioral impact factors (i.e., psychoeducation, goal setting), that are applied by a psychologist via structured feedback. Single-blinded assessments will be conducted at baseline, following the intervention period of 20 weeks, and at 6-month follow-up after the end of the intervention. The primary endpoint is reduction of exposure to second-hand smoke exposure assessed by urinary levels of cotinine. Secondary endpoints in ELIPSE-II include changes in parental smoking habits and effects of the intervention on infants' respiratory health. A further endpoint is acceptance and usability of the app.
