Abstract
AIMS: Physical activity interventions are recommended for community-based youth mental health services to prevent physical health disparities. Implementation is challenging, and studies focusing on the methods to achieve change are needed. This study aims to identify the context, implementation strategies, and implementation outcomes that illustrate how physical activity interventions were implemented within an early intervention service in Australia. METHODS: A theoretically informed case study was undertaken. Data from a community-based youth mental health service that delivers an early psychosis programme were collected between July and November 2020. Three data sources were accessed (1) interviews with service managers, mental health clinicians and exercise physiologists; (2) document review of organizational policies and procedures; and (3) survey using the Program Sustainability Assessment Tool. The implementation outcomes investigated were acceptability, fidelity, penetration, and sustainability. Framework analysis was used, and a logic model developed guided by an established template, to interpret findings. RESULTS: Forty-three contextual factors and 43 implementation strategies were identified. The data suggests that creating a new clinical team and auditing and feedback are critical for implementation. High levels of acceptability and sustainability were described, while fidelity of implementation was difficult to establish, and penetration was low. CONCLUSIONS: The relationship between constructs suggests several mechanisms underpinned implementation. These include changing professional beliefs, establishing new organizational norms, augmenting existing work processes, and aligning physical activity with priorities of the mental healthcare system and existing work tasks. This case study provides direction for future health service planning of physical activity interventions in community-based youth mental health service.