Considering Instructional Contexts in AAC Interventions for People With ASD and/or IDD Experiencing Complex Communicative Needs: A Single-Case Design Meta-Analysis
Review Journal of Autism and Developmental Disorders
Ganz, J. B., Pustejovsky, J. E., et al. (2023).
Review Journal of Autism and Developmental Disorders, 10(4), 615-629.
This systematic review and meta-analysis investigates the effects of AAC intervention for children with complex communication needs who also have intellectual and developmental disabilities or who are on the autism spectrum.
Institute of Education Sciences, U.S. Department of Education,
2018-2020
Single-case experimental design studies
114
The average effect size was Tau(AB) = 0.72 (95% CI = [0.67, 0.77]) across all participants and outcomes; effects were heterogeneous. The average LRR effect size was 1.86 (95% CI = [1.58, 2.13]) across all participants and outcomes and was also heterogeneous. For each, across all participants, effects were larger for AAC-related than communication-related outcomes. Trends were similar for the subset of children on the autism spectrum (LRR = 2.125 for AAC outcomes vs. LRR = 1.374 for other communication outcomes). For children with intellectual and developmental disabilities, effect sizes for AAC-related outcomes were smaller than other communication-related outcomes (LRR = 1.683 vs. LRR = 1.962 respectively).
Moderator analysis of effect sizes for AAC-outcomes was conducted with respect to variation across instructional setting (i.e., home, clinic, or classroom). For Tau(AB) effects and LRR effects, differences were not statistically significant.
For AAC-related outcomes, the number of instructional features was not significantly associated with Tau(AB) effect sizes in the overall sample, nor for subsamples of children with intellectual and developmental disability or on the autism spectrum. Differences in Tau(AB) effects were noted for the use of modeling in the overall sample; with average effects of 0.69 when implementing modeling and 0.82 for studies not implementing modeling. This difference was preserved when stratified by for children on the autism spectrum. However, differences by use of modeling were not statistically significant when controlling for participant characteristics or other aspects of instructional context. <br /><br />Similarly, the number of instructional features used was not significantly associated with LRR effect sizes for the overall sample or subsamples stratified by diagnosis. For specific instructional features, significant differences were seen for studies implementing physical prompting (average effect sizes of 2.42 for studies implementing physical prompts and 1.39 for those that did not). Similar results were seen in children on the autism spectrum (average effects of 1.91 when implementing physical prompting and 0.66 for studies that did not), even when controlling for participant characteristics or other aspects of instruction.
Effect sizes were also compared for behavioral vs. naturalistic intervention strategies. Tau(AB) effect sizes were not statistically significant for the use of more behavioral intervention strategies across all participants. Results were significant for children on the autism spectrum; using one additional behavioral strategy was associated with a difference of β = 0.084. For specific intervention strategies, none was statistically significant across all participants or for children with intellectual and developmental disabilities. For children on the autism spectrum, interventions conducted in controlled environments were associated with statistically higher effects than those in naturalistic environments; although, the difference was no longer significant when controlling for participant characteristics and context variables. <br /><br />For LRR effects, the number of behavioral strategies used was not significantly associated with effect size for AAC-related outcomes. Similarly, no individual behavioral strategy showed a statistically significant association with LRR effect sizes.
