Process evaluation of the digital Health4Life intervention among a sample of disadvantaged adolescents and teachers.

Disadvantaged adolescents, including those from lower socioeconomic status (SES) or geographically remote backgrounds, engage in higher rates of risk behaviours, including poor diet, alcohol and tobacco use. While digital interventions targeting lifestyle risk behaviours show potential, few studies have focused on their implementation and relevance for this population. This study conducted a process evaluation of 'Health4Life', a universal school-based digital program targeting multiple behaviours, among a sample of disadvantaged adolescents. Participants were from six schools classified as low SES (Index of Community Socio-educational Advantage percentile score ≤ 25%), and/or regional using the Australian Statistical Geography Standard. Self-reported student (n = 214) and teacher evaluations (n = 16) assessed Health4Life's acceptability, with qualitative questions capturing areas for improvement. Teacher-reported implementation data (n = 16) measured intervention fidelity and feasibility. Quantitative data were analysed using descriptive statistics and open-ended responses were thematically analysed. Compared to the entire sample, this subset of students evaluated Health4Life less favourably (66% versus 75%), with fewer enjoying the stories (63% versus 75%) and planning to use the skills and information (60% versus 70%). Teacher evaluations were mostly positive and aligned closely with the entire sample. Fidelity data also indicated comparable levels of student engagement (~92% versus ~85%). Key themes for refinement included improving content relevance and technical execution to better resonate with disadvantaged adolescents. While teacher evaluations suggest Health4Life is a valuable program in low SES or regional contexts, students' lower ratings indicate refinements are needed. Identified areas for improvement will guide co-designing the program's adaptation to improve effectiveness and relevance for disadvantaged adolescents. Trial registration: The Health4Life trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12619000431123).