Project report

Trial protocol: A hybrid effectiveness-implementation study of Paediatric Autism Communication Therapy (PACT) in the Brazilian public health system

Godoy PBG, Windlin IC, dos Santos Cardoso LM, Yoshida J, Lopes DCP et al. · 22 Jun 2026

Abstract

In Brazil, autistic children and their families face significant challenges in accessing evidence-based interventions, especially via the national public health service. Here, we report the protocol for a hybrid effectiveness-implementation trial, which will investigate the large-scale implementation of Paediatric Autism Communication Therapy (PACT) as well as its real-world effectiveness in Brazilian public health services for autistic children. Eligible professionals from public health services across the five regions of Brazil will be trained in PACT. They will deliver the intervention, which consists of 14 sessions delivered over 6 months, to dyads of autistic children and their caregivers in their regular clinical practice for the trial period of 18 months. We will use elements of three implementation science frameworks to systematically study factors that influence the implementation of PACT in this setting. To study effectiveness dyads will be randomised to receive PACT immediately or following a 6-month waitlist, stratified by healthcare service. Effectiveness outcomes (parent-child interaction, child adaptive social communication skills, caregiver well-being) will be collected pre- and post-PACT/waitlist and compared between groups. This trial will provide the first evidence on the effectiveness of PACT implemented in a public health system and the barriers and facilitators to such large-scale implementation. Lay abstract In Brazil, many autistic children and their families struggle to access early, evidence-based support through the public health system. This study aims to help change that. We will test how a well-established intervention, called Paediatric Autism Communication Therapy (PACT), can be delivered at a large scale in Brazilian public health services, and whether it works effectively in real-world conditions. PACT works by helping caregivers understand their autistic child’s communication and to respond in supportive ways that promote their child’s social communication development. For this project, professionals from public health services across all five geographical regions of Brazil will receive training to deliver PACT to autistic children and their caregivers as part of their routine clinical work. Each family will be offered 14 sessions over six months, and the study will run for a total of 18 months. To understand how PACT can be used successfully across the Brazilian public health services, we will examine what helps or hinders implementation using established frameworks from implementation science. We will also evaluate how well the intervention works by comparing families who start PACT immediately with those who begin after a short wait. We will assess changes in caregiver-child interactions, children’s social communication and well-being, and caregiver well-being. This will be the first study to examine an evidence-based therapy for autistic children and their caregivers implemented at scale in the Brazilian public health system. The findings will guide policymakers, health services, and communities on how to improve access to high-quality early support for autistic children and their families in Brazil.