Prevention and Reduction of Anxiety in Autistic Preschoolers Through an Autism-Specific Parent-Mediated Intervention: A Pilot Randomised Controlled Trial Evaluating Short and Longer Term Outcomes.

The study was underpowered, recruiting 57 participants against a target of 64, and is explicitly described as a pilot. The intervention group had significantly higher baseline anxiety scores than the control group, which complicates between-group comparisons and raises the possibility of regression to the mean. Outcomes were based solely on parent-report, and parents were aware of their group allocation, introducing potential bias. The 'longer-term' follow-up was only about 15 months, which is insufficient to determine if benefits persist through childhood. Families with lower incomes were more likely to drop out, limiting the generalisability of the findings to these groups.

The authors declared no competing interests. The study was funded by the Australian Research Council and Griffith University.

Do not interpret the lack of significant between-group differences in total anxiety at follow-up as a failure of the intervention. The intervention group started with higher anxiety levels than the control group, so their significant within-group reduction represents a convergence towards the control group's baseline rather than a lack of effect. However, given the small sample size and baseline imbalance, these findings require confirmation in a fully powered trial.