Gardening is a balanced melding of the natural growth of plants and the intervention of a gardener. Sometimes it feels right to let your garden take over,

Routine Early Intervention services are an ideal context to evaluate parent-mediated intervention (PMI) delivery. While effectiveness research suggests that receiving manualized PMIs positively affects caregivers’ learning and use of intervention strategies, the impact of other aspects of delivery, such as PMI adaptation, on caregiver engagement and learning is less clear. The current study aimed to address this gap by closely characterizing the delivery and associated outcomes of an autism PMI, Project ImPACT, within an Early Intervention (EI) Part C system. In total, 21 EI providers and 23 caregivers of children with social communication delays participated. Following training in Project ImPACT, the providers submitted videos of their Project ImPACT sessions as part of routine service delivery. The sessions were behaviorally coded for Project ImPACT coaching fidelity and instances in which Project ImPACT was adapted. After each session, the caregivers rated their participatory engagement and therapeutic alliance. Before and immediately following the intervention, the caregivers also completed measures of their self-efficacy and their child’s social communication skills, and their use of Project ImPACT strategies (i.e., fidelity) was behaviorally coded. The results demonstrated that EI providers’ Project ImPACT coaching fidelity was not related to caregiver ratings of therapeutic alliance or participatory engagement at the session level. Augmenting Project ImPACT sessions was associated with higher caregiver ratings of therapeutic alliance but not with participatory engagement. Although provider coaching fidelity was not associated with changes in caregiver ratings of self-efficacy, it was associated with caregiver use of Project ImPACT strategies focused on teaching their children new skills. There was no association between provider fidelity and caregiver report of child social communication outcomes. The current study highlights the complicated relationship between the delivery of autism PMIs and caregiver-reported outcomes. The findings highlight the value of holistic delivery models that support adaptations in response to child- and family-level factors.