Occupational Therapy Faculty Publications

Clarifying the ABA Comparison and Equivalence Claims in Schaaf et al. (2025)

Document Type

Letter to the Editor

Publication Date

1-12-2026

Abstract

Dear Editor,

I am writing to express concerns regarding Schaaf et al.'s article, “A Comparative Trial of Occupational Therapy Using Ayres Sensory Integration and Applied Behavior Analysis Interventions for Autistic Children” (Schaaf et al. 2025). Considering the potential impact this study has on service recommendations, I would like to discuss the concerns that, in my opinion, hinder the conclusions that can be drawn.

First, the “Applied Behavior Analysis (ABA)” arm appears to represent a brief, focused behavioral skills training (30 one-hour sessions over several months in a clinic room). This protocol, however, is not a comprehensive, high-intensity ABA model implemented in practice following contemporary practice guidelines (typically 20–40 h per week across settings and domains, Council of Autism Service Providers (CASP) 2024). To extrapolate from this low-dose, limited protocol to what ABA normally enacts in practice is to risk overstating both the scope and the evidence for ABA.

Second, the trial was powered only to detect very large effects, yet the non-significant between-group difference on the pre-specified primary outcome (PEDI-CAT Daily Activities) is interpreted as evidence that OT-ASI and ABA achieved “comparable” improvements. According to the CONSORT guidance on noninferiority and equivalence trials (Piaggio et al. 2012), clearly stated, failure to show superiority in an underpowered study does not establish equivalence.

Third, the more positive finding in Schaaf et al. relies heavily on Goal Attainment Scaling (GAS), an individualized, caregiver-reported outcome obtained post-treatment. Although valuable, GAS is more vulnerable to expectancy and allegiance effects than the blinded, standardized primary outcome, a limitation that is not emphasized in the discussion.

I appreciate the authors' efforts to undertake a complex randomized trial. However, I would encourage a more cautious discussion of the equivalence between OT-ASI and ABA and a broader recognition that the ABA condition as administered in their study is not equivalent to how average ABA programs in clinical practice are delivered.

Comments

© 2026 International Society for Autism Research and Wiley Periodicals LLC.

Publication Title

Autism Research

DOI

10.1002/aur.70184

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