Optimising a digital intervention to support parents experiencing socio-economic disadvantage to improve adolescent health behaviours: Protocol for the Health4Life Parents & Teens factorial trial

Abstract

Background: Youth experiencing socio-economic disadvantage often have elevated rates of health risk behaviours. Although adolescence is a time of increasing autonomy for youth, parents continue to play a significant role in their health. Parent-based interventions can reduce barriers faced by families experiencing disadvantage and improve adolescent outcomes. However, few such interventions addressing multiple risk behaviours exist for this population. This study aims to: i) systematically test the individual and synergistic effects of four parent-based intervention components, and ii) assemble an optimised intervention in which all components are effective in improving parental encouragement of adolescent health habits, while imposing the least possible burden on parents. Methods: Guided by the Multiphase Optimisation Strategy, we will conduct a 24 factorial trial with 389 parents of adolescents in Australia. All parents will receive six online modules (screen time, smoking/vaping, alcohol, sleep, food/nutrition, physical activity). Parents will be randomised to receive 1 of 16 combinations of additional components: text messages, tailored feedback, stress management, and health coaching. Parents will complete surveys at baseline and 3-months post-baseline. The primary outcome is change in parental encouragement of adolescent health habits at 3-months (proximal outcome). Parent's health behaviours, self-efficacy, stress, communication and the acceptability and burden (perceived effort to complete) of each component will also be assessed. Discussion: This study will result in a digital intervention for families experiencing socio-economic disadvantage that is as effective as possible in improving parental encouragement of adolescent health habits, and that can be delivered with minimal burden, which is critical for translation. Trial registration: The trial was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12624001492549 date registered: 20/12/2024).