Dissemination strategies for the national scale-up of a school-based physical activity initiative: insights from education and health sector partner organizations

Background Whole-of-school physical activity initiatives have strong potential for population-level impact, yet few have been disseminated or scaled nationally. Given the relative lack of dissemination research compared with implementation research in this field, and the limited exploration of third-party perspectives, this study aimed to examine how cross-sector partner organizations disseminated TransformUs Secondary to schools across Australia. Methods This qualitative study was incorporated into the TransformUs Secondary type 2 hybrid implementation–effectiveness trial. Sixteen partner organizations were invited to participate in online semi-structured interviews conducted 16-months post-launch. Interview transcripts were analyzed using reflexive thematic analysis, with findings organized into three major themes: dissemination strategies (types, frequency, pathways), barriers and enablers influencing partners’ dissemination efforts, and mechanisms underlying perceived effective dissemination strategies. Results Out of 16 invited partner organizations representing diverse sectors, 10 participated in interviews. Partners employed multiple dissemination strategies, including different types (i.e. material development and distribution, educational meetings, and network mobilization), frequency (i.e. ranging from one-off email blasts to ongoing dissemination), and pathways (i.e. education-sector direct school engagement versus health-sector intermediary-led dissemination, each characterized by distinct channels and message framing). Partners’ dissemination efforts were shaped by teacher-level factors (perceived complexity, relevance, workload pressures), partner organizational factors (bureaucratic processes, role boundaries, limited capacity), and system-level factors (funding and competing priorities). Partners perceived that effective dissemination required not only access to resources, but also strategies that built implementer capacity, strengthened positive attitudes, and fostered school-level engagement. Conclusions These findings are novel in highlighting how national dissemination of a school-based physical activity initiative operates across diverse partners, showing that dissemination pathways, channels, and messages are shaped by the actors involved, and extend beyond simply sharing materials. Future research should design and test dissemination strategies, as well as explore how they interact with contextual barriers to optimize dissemination outcomes. Policy should support partner organizations to navigate organizational and system challenges, while researchers strengthen partner dissemination efforts. Trial registration This study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) under the identifier ACTRN12622000600741 on 21 April 2022.