A cluster randomised controlled trial of an eHealth intervention to prevent multiple lifestyle risk behaviours among Australian adolescents: Results from the Health4Life Study

Alcohol use, smoking, poor diet, physical inactivity, screen time and poor sleep ('the Big 6') are associated with poor physical and mental health outcomes. The Big 6 emerge during adolescence, commonly co-occur and track into adulthood. This study aims to evaluate the efficacy of Health4Life, an eHealth intervention to concurrently prevent the Big 6 among school students.

A cluster randomised controlled trial was conducted in 71 Australian schools, with schools randomised to Health4life or health education as usual. Health4Life consists of i) six web-based cartoon modules and a smartphone application (universal prevention for all Grade 7 students), and ii) additional app content, delivered to high-risk students when they are in Grades 8 and 9 (selective prevention). Students completed self-report questionnaires at baseline, post-intervention, 12- and 24-months. Outcomes were self-reported Big 6 and composite risk index scores (sum of the Big 6). Multilevel growth models were conducted, with repeated observations nested within students and students clustered within schools. We declare no conflicts of interest.

A total of 6640 students (Mage=12.7 yrs; 50% female) completed baseline assessments in 2019. 83% of the sample were retained at 12 months; 75% at 24-months. Preliminary analyses indicate that compared to controls, students who received Health4Life had significantly lower composite risk scores (sum of the Big 6) (ß=-0.09, 95% CI=-0.16, -0.02) at 12 months. Analysis of 24-month data is underway.

This is the first evaluation of an eHealth school-based intervention to simultaneously target six key lifestyle risk factors among adolescents. Results suggest that the Health4Life is effective in modifying the Big 6 in the short-term, however further research is needed to determine if effects can be sustained over time.