Empirically-Derived Effect Size Distributions of Interventions for Young Children on the Autism Spectrum.

Researchers looked at data from 144 studies of autism interventions for young children to create helpful reference guides. They found that intervention effects vary greatly depending on what skill area is being measured and how it's measured. These reference guides help researchers and practitioners better understand whether an intervention's results are small, medium, or large compared to other similar studies.

This meta-analysis examined 1,552 effect sizes from 144 early childhood autism intervention studies to create empirically-derived benchmarks for interpreting intervention effects. The researchers developed effect size distributions across different outcome domains and measurement characteristics (boundedness, proximity, assessment approach). Results showed considerable variability in effect sizes depending on the specific outcome domain and how outcomes were measured. These benchmarks provide field-specific reference points for researchers to interpret whether intervention effects are small, medium, or large relative to existing literature, and assist in planning future studies through improved power analyses.

Provides practitioners with evidence-based benchmarks to evaluate intervention effectiveness relative to the broader research literature. Assists in intervention selection by offering context for interpreting study results. Supports more nuanced discussions about intervention outcomes with families and team members by contextualizing effects within field-specific reference points.

The abstract does not specify limitations of the data or analyses. The authors acknowledge limitations exist but do not detail them in the abstract. The reliance on existing studies means benchmarks reflect current research quality and methodological approaches in the field.

The purpose of this study is to present a set of empirically derived effect size distributions to provide field-based benchmarks for interpreting the observed effects of interventions for young children on the autism spectrum, and for planning future studies. We generated effect size distributions and reported quartile values for each by outcome domain, and by boundedness, proximity, and assessment approach using 1552 effect sizes from 144 early childhood autism intervention studies gathered for a previously published meta-analysis. Quartile values represent considerable heterogeneity in effect size distributions across outcome domains, as well as variability as a function of outcome boundedness, proximity, and assessment approach. Our results serve as field- and outcome-specific benchmarks (e.g., contextual guides for small, medium, and large effects) that will help autism intervention researchers easily incorporate information from relevant prior empirical literature when conducting power analyses to plan for future studies.

Benchmarks will also assist researchers seeking to interpret the magnitude of observed effects in clinical trials relative to the broader distribution of intervention effects on similar outcomes. Nuanced discussions that contextualize study findings in light of relevant empirical benchmarks will better assist practitioners in understanding the magnitude and scope of demonstrated change relative to studies with similar outcomes and selecting interventions for clinical practice. We discuss the limitations of these data, our analyses, as well as directions for future work.