RESUMEN
BACKGROUND: While effective interventions have been developed to support families where a parent has a mental illness in Adult Mental Health Services, embedding and sustaining them is challenging resulting in families not having access to support. This study developed an explanatory model of influencers that had enabled sustainability of the Let's Talk intervention in one service. METHODS: A participatory case study was used to build an explanatory model of sustainability at the service using theoretical frameworks. Qualitative and quantitative data was collected about practitioner's practice and the organisation's implementation process and capacity to support practice. A local research group worked with the researcher using a transforming data approach through description, analysis and interpretation. RESULTS: Influencers were grouped into four major categories: (1) External social, political and financial context, (2) Resources, (3) Prior organisational capacity and (4) Sustainability Factors. The last category, Sustainability factors, was divided into three subcategories: (4.1) Practitioner (4.2) Organisation and (4.3) Parent-Client. These categories form part of an explanatory model for the key influencers of continued practitioner practice and organisational capacity to support practice. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: In this case study, the pre-existing organisational context along with practitioner, organisation and parent-client factors operated together to influence sustainability. The results suggest that sustainability is more likely to be supported by both linking Let's Talk to existing organisational identity, capacity, structures and relationships and by supporting mutual adaptations to improve the fit. Additionally, by understanding that setbacks are common and ongoing adjustments are needed, implementers are able to have realistic expectations of sustainability.