Effectiveness of Parent-Mediated Interventions for Autism Spectrum Disorder: A Meta-Analysis of Outcome Domains and Domain-Specific Effects

This systematic review and meta-analysis examines the overall effectiveness of parent-mediated interventions (PMIs) for autistic individuals and whether intervention effects differ across outcome domains. The primary aim is to estimate the overall post-intervention effectiveness of PMIs relative to eligible control conditions in randomized controlled trials. Further aims are to identify the outcome domains assessed in controlled PMI studies, estimate domain-specific effects, and examine outcome domain as a prespecified moderator of intervention effect. Randomized controlled trials will form the primary evidence base. Controlled non-randomized intervention studies will be considered separately in secondary or sensitivity analyses. Multiple eligible and conceptually non-redundant effect sizes reported within individual studies will be retained where possible and analysed using multilevel meta-analytic models that account for statistical dependency. Outcome domain will be investigated as the primary prespecified moderator. The review will include outcomes relating to the autistic participant, the parent or caregiver, and the parent-child dyad. A preliminary outcome taxonomy will be defined before full study selection and may be refined during pilot coding according to prespecified conceptual criteria. The review will follow PRISMA-based reporting principles. This registration documents the eligibility criteria, search strategy, screening procedures, outcome coding rules, handling of dependent effect sizes and multiple study arms, risk-of-bias assessment, and planned statistical analyses before completion of the systematic study-selection and quantitative synthesis.