Objectives The primary objective of this study is to evaluate the effectiveness of the SREIA parent training program for families of children with ASD aged three to six years in mainland China. The study will be conducted within the context of routine service provision and assess the effectiveness of SREIA in reducing child behavioral problems as measured by the Externalizing scale of the Child Behavior Checklist (CBCL) for Ages 1.5-5, in comparison to a waitlist control group.

Secondary objectives include examining the effectiveness of the SREIA program in reducing ASD symptoms and improving parental and familial outcomes including parental knowledge of ASD and ABA techniques, parenting styles, parental mental health (including stress, anxiety and depression), and family functioning.

A process evaluation will be conducted alongside the quasi-experimental trial, the objectives of which are to 1) describe the implementation aspects of the programs with regard to participant involvement, program acceptability, delivery, and sustainability; 2) explore predictors of participant involvement; and 3) examine potential relations between implementation aspects and treatment effects.

Background ASD is associated with elevated levels of child emotional and behavior disturbance, which impair child daily functioning and impose challenges to parenting. The SREIA programme is a group-based parent training in China, that has been delivered since 1993 and reached over 10,000 families. However, there is an absence of scientific evaluations of programme effectiveness. This study aims to fill this evidence gap, and the findings will be used to inform future modification, replication, and dissemination of the programme in other parts of China. This study will also contribute to the literature on the effectiveness of parent training programmes for ASD and for families living in low- and middle-income countries.

Methods A quasi-experimental design with a mixed-methods approach will be used, involving two consecutive waves of delivery of the SREIA programme. Parent participants will complete demographic and outcome questionnaires at baseline, immediate post-intervention, and 1- or 1.5-year post-intervention (conditional to funding). The implementation components will be assessed by collecting attendance and engagement registry data, facilitators filling out fidelity checklists, research staff observing programme sessions, and parents answering a satisfaction questionnaire. After the programme, some parents, facilitators, and NGO (non-governmental organisation) managers will be invited to take part in qualitative interviews or focus group discussions so as to explore their views about the programme, and to better understand the quantitative data obtained.

The recruitment criteria for parents/primary caregivers from families with children with ASD will follow the existing strategies used by of the implementation organisation. Each primary caregiver will have one child participating in the program. Participating primary caregivers will be those who:

• Aged 18 or older,
• Undertake the responsibility for the daily care of a child between the ages of 3 and 6 years for at least 5 days a week,
• target child meets the diagnostic criteria for Autism Spectrum Disorder according to DSM-V (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition); otherwise, an official letter of ASD diagnosis should be provided, and
• Provide informed consent to participate in the research.

Facilitator Inclusion Criteria:

• Aged 18 or older,
• Employees of the implementation organisation,
• Participate in the delivery of the program during this study, and
• Provide informed consent to participate in the research.

Program Manager Inclusion Criteria:

• Aged 18 or older,
• managers of the program, and
• Provide informed consent to participate in the research.

Parent/Primary Caregiver Exclusion Criteria:

• Parents/primary caregivers will be excluded if the child has been diagnosed with Cerebral Palsy. There will be no additional exclusion criteria.

The data will not publicly available due to ethical requirements in the University of Oxford but will be available from the corresponding author on reasonable request.

Due to the nature of parent training and the use of a waitlist control group, it will not be possible to blind participants or facilitators. However, research staff who collect the data will be blinded for the baseline and post-intervention assessment. Data collectors will not be involved in the delivery process and will be trained on the topic of risk of bias. Parents will also be asked not to reveal their allocation condition to outcome data collectors. Process evaluation data will be collected by a separate group of research staff. Given that all families will ultimately receive the training, blinding will not be possible at the follow-up time-points. Blinding will be protected and monitored, while the violation of blinding will be detected and incorporated into the interpretation of results.