Early Life Intervention in Paediatrics Supported by E-Health (ELIPSE)-a coaching app for parents to reduce obesity and second-hand smoke exposure in children: study protocols for two parallel-group randomised controlled trials.

BACKGROUND: Family lifestyle factors-such as physical activity, diet and parental smoking-are key modifiable determinants for child health. Physical inactivity and calorie-dense diets contribute to obesity, which is linked to 75% of all non-communicable diseases (NCDs). Second-hand smoke (SHS) exposure significantly increases the risk of respiratory NCDs in children, including asthma. Cognitive behavioural therapy (CBT) has proven effective in modifying harmful parental behaviours, but it remains unclear whether app-based CBT for parents can improve family behaviours and child health outcomes. The Early Life Intervention in Paediatrics Supported by E-Health (ELIPSE) project aims to implement and evaluate personalised, family-centred, guided e-health interventions delivered via the ELIPSE mobile app. METHODS: In two randomized controlled trials (ELIPSE I and II), the ELIPSE app will deliver CBT elements, tailored thematic content, and personalised feedback, all remotely guided by a coach. In ELIPSE I, 148 parent-child dyads (child age 6-12 years, BMI > 97th percentile) are randomly assigned 1:1 to treatment as usual (TAU; control group) versus TAU plus full access to the activated ELIPSE app (intervention group). The primary endpoint is the change in children's ratio of total energy intake to total energy expenditure (TEI/TEE). Secondary endpoints include obesity severity and cardiometabolic risk factors. In ELIPSE II, 160 dyads of a smoking parent and child (< 6 years) are randomly assigned 1:1 to receive either a leaflet on protecting children from SHS exposure (control group) or access to the activated ELIPSE app (intervention group). The primary endpoint is the change in children's urinary cotinine levels. Secondary endpoints include parental measures to reduce SHS exposure. The intervention period for both trials is 20 weeks, with outcomes assessed at baseline, post-intervention, and 48-week follow-up. DISCUSSION: The ELIPSE project offers a novel approach to addressing key modifiable NCD risk factors within the family environment, with the goal to improve long-term child health outcomes and reducing morbidity and healthcare costs. Unlike traditional care, the ELIPSE app overcomes time and space constraints, allowing continuous support and personalised guidance. TRIAL REGISTRATION: Both trials prospectively registered at ClinicalTrials.gov: ELIPSE I as NCT06208345 (15 January 2024); ELIPSE II as NCT06311162 (7 March 2024).