A Community-Based Randomized Comparison of Speech Generating Devices and the Picture Exchange Communication System for Children with Autism

Background: Extensive research has established the Picture Exchange Communication System (PECS) as evidence-based practice for establishing functional communication in nonverbal and minimally verbal children with autism. However, despite strong preference of both families and users to utilize high-tech augmentative and alternative communication systems, such as tablet-based speech-generating devices (SGDs), definitive evidence on the relative effectiveness of SGDs versus PECS for communication training is lacking.

Objectives: To determine the relative effectiveness of SGD versus PECS based communication intervention in a community-based intervention setting, we conducted a randomized controlled trial directly comparing the impacts of SGDs and PECS to an Education As Usual (EAU) comparison control in specialist schools for children with autism in Ireland.

Methods: Nonverbal and minimally verbal students diagnosed with Autism Spectrum Disorder were randomized at the classroom level to receive 2 months of communication intervention via SGD (n=15) or via PECS (n=13), versus EAU (n=13). Experimental change measures were scored from a live interaction previously developed to index unprompted communicative functions, including mands, intraverbals, and tacts, which was administered to all participants at both pre- and post-training.

Results: The groups did not differ on either chronological age or levels of communication at intake. Statistical analyses further indicated significant increases in rates of total communication in both the SGD and PECS groups, each compared with the EAU condition, which was driven by significant increases in overall communication from pre-training to post-training in both conditions. Further analyses indicated that neither total communication nor manding differed for the SGD versus PECS conditions.

Conclusions: The results of this study provide experimental evidence indicating that school-based implementation of communication intervention via SGD and via PECS are each effective for establishing basic functional communication skills, with each modality providing significant improvements above and beyond education as usual. Critically, these effects were driven by significant increases in rates of manding in both conditions, and communication improvements did not differ between the high-tech and low-tech intervention conditions. Taken together, these results provide further support for both high-tech and low-tech augmentative and alternative communication intervention strategies as evidence-based practice for establishing basic functional communication skills for children with autism.