Outcomes of participating in the Let's Play programme on 0-5-year-old autistic children's engagement and caregivers' stress: study protocol for a parallel randomised controlled trial.

Researchers are planning to study a 9-week parent training program called Let's Play for families with autistic children under 6 years old. The program teaches parents how to help their children learn and engage through everyday activities and play. They will compare families who get the program right away to those who wait, measuring how well children engage and how stressed parents feel. Results aren't available yet as this is just the study plan.

This is a study protocol for a randomised controlled trial evaluating Autism New Zealand's Let's Play programme, a caregiver-mediated developmental intervention for autistic children aged 0-5 years. The programme combines small group workshops with in-home coaching over 9 weeks, based on developmental and relational intervention principles delivered in naturalistic settings. The trial will compare immediate programme access versus waitlist control, measuring child engagement and caregiver stress as primary outcomes. The study aims to recruit 64 caregiver-child dyads and will assess outcomes at baseline, post-programme, and 6-month follow-up using intention-to-treat analyses.

No clinical implications can be determined as this is a protocol paper describing planned research methodology. Once completed, this RCT may provide evidence for the effectiveness of caregiver-mediated developmental interventions in community settings for young autistic children and their families.

This is a study protocol only - no results are available yet. The study has not been conducted, so no limitations of findings can be assessed. The research is still in the planning phase.

Vast empirical evidence highlights the importance of early identification, diagnosis and support for autistic children. Caregivers of autistic children often experience high levels of psychological distress; hence there is a need for parallel child and caregiver support. Autism New Zealand's Let's Play programme is a caregiver-mediated, community-based programme based on the principles of developmental and relational interventions (henceforth, developmental). Developmental interventions are evidence-based supports designed to enhance children's learning within the context of developmentally appropriate, naturalistic settings (eg, everyday routines, play).

We aim to evaluate the effects of the Let's Play programme on autistic children's engagement and caregiver stress. This study will be a single-blind (rater) randomised controlled trial with two parallel arms: immediate programme access (intervention) versus a waitlist control. Participants will be 64 caregivers of children aged 0-5 years with diagnosed or suspected autism, allowing for 20% attrition, based on power calculations. The Let's Play programme will be delivered over 9 weeks using a combination of small group workshops and in-home coaching.

Primary outcome variables include child engagement and caregiver stress. Caregivers will complete measures at three time points (baseline, immediately post-programme and at the 6-month follow-up), and effectiveness will be analysed using generalised estimating equation models and intention-to-treat and per protocol analyses. This trial was approved by Aotearoa New Zealand Ministry of Health's Health and Disability Ethics Committee (2022 FULL 13041). Findings will be communicated nationally and internationally via conferences, journal publications and stakeholder groups (eg, service providers for autistic children).

Results will be shared regardless of magnitude or direction of effect. ACTRN12622001139763.