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

ABSTRACT

Objective

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.

Method

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.

Results

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.

Conclusions

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.

Disclosure Statement

No potential conflicts of interest were reported by the author(s).

Supplementary Material

Supplemental material for this article can be accessed online at https://doi.org/10.1080/15374416.2021.2007485.

Notes

¹ Although professional journals often require the use of person-first language (e.g., person with autism), many autistic people have expressed a preference for identity-first language (e.g., autistic person), because they conceptualize autism as an inherent aspect of identity which is not separable from their personhood. Recently, autistic scholars have suggested “on the autism spectrum” as the linguistic construction deemed the least offensive by stakeholders (Botha et al., 2021). In this paper, we have elected to use “children on the autism spectrum” and “autistic children” to describe this population. We also elected to use “autism” in lieu of “autism spectrum disorder” as the latter term uses deficit-focused language that may offend autistic readers without enhancing clarity (Robison, 2019).

² We acknowledge that while “challenging behavior” is a commonly used term in autism research, it does not specify for whom the behavior is perceived as challenging. Autistic people may view behavior categorized as “challenging” as an adaptive response to unsupportive environments (Ballou, n.d.; Bottema-Beutel et al., 2021).

Additional information

Funding

This work was supported, in part, by the National Institutes of Health [1R21DC016144].