Mapping the type, frequency, intensity, temporality, and pathways of dissemination strategies during the national scale-up of TransformUs Secondary.

BACKGROUND: Schools are ideal settings for implementing evidence-based physical activity interventions at scale due to their wide reach. However, dissemination strategies used to achieve scale are rarely reported. PURPOSE: This study aimed to describe the strategy type, frequency, intensity, temporality, and pathways used in disseminating the TransformUs Secondary initiative across Australia over the first 16 months of national scale-up. METHODS: TransformUs Secondary is a whole-of-school initiative that targets behavioral, environmental, and pedagogical strategies inside and outside the classroom to reduce sedentary behavior and increase physical activity among adolescents aged 12-18 years. Since October 2023, the TransformUs team and 16 partner organizations collaboratively disseminated the initiative nationally. A dissemination activity log was used to record dissemination strategies, which were subsequently mapped post hoc to existing frameworks to categorize type, frequency, intensity, temporality, and pathways. Data are reported descriptively and graphically. RESULTS: Between October 2023 and February 2025, 10 discrete strategies were identified, with the most frequent and intensive strategies being "Promotion via mass media" (33.2%, 110 person-hours), "Develop educational materials" (20.8%, 48 person-hours), and "Maintain partner engagement" (12.4%, 20 person-hours). Strategy frequency and intensity fluctuated and increased after the initiative launch, shifting the focus from targeting partner organizations to targeting school staff. Notably, 54.3% of dissemination strategies occurred via direct pathways to school staff. CONCLUSION: Reporting dissemination strategies and pathways clarifies how school-based interventions are scaled in practice, providing evidence to inform research, guide policy, and support effective implementation in schools. CLINICAL TRIAL INFORMATION: The Clinical Trials Registration #ACTRN12622000600741.