Assessment of improvement in anxiety severity for children with autism spectrum disorder: The matched correspondence analysis approach.

Background: Clinical trials typically involve random assignment to treatment conditions. However, random assignment does not guarantee a lack of systematic variation in the outcomes, and application of covariation methods for multiple dependent measures requires complicated assumptions that are often not met.

Methods: This study employed matched correspondence analysis (CA) for controlling systematic variation and handling multiple outcomes. One hundred nine children with autism spectrum disorder (ASD) were assessed for anxiety symptom severity across four studies, where participants were randomly assigned to either cognitive behavioral therapy (CBT) or treatment as usual or waitlist (TAU/WT). Matched CA is designed to optimally scale only the differences between baseline and posttreatment, rendering the systematic baseline carryover effects irrelevant.

Results: Differences in treatment efficacy were observed. CBT showed treatment efficacy on anxiety severity and anxiety-related impairment relative to TAU/WT, after the control of baseline carryover effects.

Conclusions: This study provides a way to control systematic variation between groups at the outset of treatment trials and is expected to provide a novel pathway to more proper assessment of treatment efficacy for children with ASD and anxiety.