Understanding digital diffusion and online decision-making in public health promotion: a sequential mixed-methods study of the violence prevention charter in Canada.

Digital environments have become important settings for public health promotion, yet dissemination alone does not explain why individuals and organizations choose to adopt and act on public health information. Understanding digital diffusion requires attention to temporal patterns of adoption, the social networks through which information and influence circulate, and the contextual conditions that shape decision-making. This sequential mixed-methods single case study examined the dissemination and voluntary adoption of the Violence Prevention Charter, a principles-based public health initiative in Canada. Website analytics and Bass diffusion modeling characterized temporal patterns of dissemination and adoption. Social Network Analysis examined the relational environment through which information, trust, and influence circulated, while a realist-informed examination of Context-Mechanism-Outcome configurations explored the contextual conditions and generative mechanisms influencing participant reasoning and engagement. The complementary findings were integrated and interpreted through a Complex Adaptive Systems framework. Digital engagement demonstrated sustained dissemination and an accelerating pattern of adoption following purposeful promotion. Social Network Analysis identified a cohesive professional network characterized by strong trust relationships, information exchange, and influential connections. Realist-informed analysis identified three principal mechanisms influencing engagement: creation of social good, trust in the source, and influence of colleagues and peers. Adoption decisions were also shaped by competing demands, characteristics of the digital environment, organizational context, and participants' independent assessment of the relevance and credibility of the initiative. The findings suggest that diffusion within digital public health ecosystems is shaped by interactions among communication, trusted social relationships, organizational context, and individual agency. Sequential integration of temporal, relational, and contextual methods provides a useful approach for investigating online decision-making and voluntary adoption, while a Complex Adaptive Systems perspective offers a framework for understanding how these interacting influences contribute to the diffusion of principles-based public health interventions.