Peer Mediated Intervention for Minimally Verbal Children with Autism Spectrum Disorders; Strength of Evidence and Future Directions

Background: Peer mediated intervention (PMI) involves engaging peers in intervention to improve social communication and/or educational outcomes for people with autism spectrum disorder. A number of reviews and meta-analyses have established PMI as an evidenced-based practice for young people with autism (Wong et al 2015; Chan et al 2009; Zhang and Wheeler 2011; Chang and Locke 2016). The majority of research published in this area is with participants who use verbal language to communicate. The evidence base for PMI with minimally verbal children with autism spectrum disorder has not been examined. This group are underrepresented in the research base in general, with Tager-Flusberg and Kasari (2013) describing minimally verbal school-aged children with autism as “the neglected end of the spectrum”. Between 25% and 30% of children with ASD can be classified as minimally verbal (Rose et al 2016). As schools become more inclusive more minimally verbal children are attending mainstream schools. Interventions that foster increased personal contact, such as PMI, may have an important part to play in fostering positive attitudes and creating opportunities for social interaction. This review aims to inform future research on PMI with minimally verbal children by investigating the current evidence base and gaps therein.

Objectives: 1) Investigate studies that implement PMI with minimally verbal children with autism. 2) Evaluate the quality of these studies. 3) Identify the outcomes targeted in these studies. 4) Consider the impact on peers involved in the studies. 5) Identify implications for practice and directions for future research.

Methods: The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology was utilised. Systematic searches of the following databases were conducted: Scopus, Web of Science, Embase, ERIC, PsychInfo and PubMed. There were no restrictions on publication date or language. Studies were included in the review if their method included PMI, the participants were children who were diagnosed with autism and were minimally verbal, and it was an original piece of research; not a review, meta-analyses or commentary. Single case and group-design studies were included. Data on study description, participant characteristics, components of intervention and outcomes, and quality of evidence were extracted from included full texts and narrative synthesis was undertaken.

Results: We present the findings in terms of eligible studies and the quality of the presented evidence. Variation in participant characteristics and processes that were used to select peer participants in the included studies are identified. Findings address details on the components of PMI as described in the studies, and the primary and secondary outcomes. We also consider the impact on the peers involved in the interventions where reported.

Conclusions: This study determines whether PMI can be considered an evidence based practice for minimally verbal people with autism. This will inform future research on PMI with this population, an area determined to require further research (Chang and Locke 2016; Watkins et al 2015).