For the evaluation of this multilevel multicomponent programme, a prospective, stratified, cluster randomised and longitudinal study was performed with an intervention group and a control group. After completion of the baseline measurements (autumn 2016), the programme Join the Healthy Boat was carried out in the intervention group, while the control group followed the regular kindergarten day-to-day life with no contact during that year. Follow-up measurements took place after one year (autumn 2017). Details on kindergarten and participants’ recruitment, materials and organisation of randomisation and data collection can been found elsewhere (Kobel et al., 2017).
973 kindergarten children in 57 kindergartens (30 kindergartens in the intervention group; 27 kindergartens in the control group), who participated in the evaluation study of the programme were assessed at baseline and 558 (57%) of them at follow-up. Prior to data collection, parents provided written and informed consent and children their assent to taking part in the study.