Design and Outcomes of a Large-Scale Randomized Trial of Parent Training for Children with ASD and Disruptive Behavior

Background:  Following the development of the parent training manual and confirmation of feasibility, we launched a multi-site randomized clinical trial in 180 children with ASD and disruptive behavior. 

Objectives: This presentation reports on the study design and primary results of the multi-site trial. 

Methods: Subjects (age 3 to 7 years) were randomly assigned to PT (n=89) or to 12 PEP sessions (n=91) for six months. As an active comparator, PEP controlled for time and attention. It provided useful information for parents of young children with ASD, but it did not include any information on behavioral strategies. The primary outcomes included the parent-rated Aberrant Behavior Checklist– Irritability subscale (ABC-I) and the Home Situation Questionnaire (HSQ), as well as the Improvement item of the Clinical Global Impression scale rated by a clinician blind to treatment assignment. The sample size of 180 was necessary to detect a small to medium treatment effect of PT over PEP. 

Results: Random regression analyses showed that PT was superior to PEP on reducing ABC-I and HSQ scores (effect sizes 0.7 and 0.5; p < 0.001 for both outcomes). Sixty eight percent (61/89) of subjects in PT were rated much improved or very much improved on the CGI-I compared to 40% (36/91) in PEP (chi square = 14.02; p <0.001). Overall attrition was 10% with no difference between groups. Attendance and fidelity were similar to results in our previous pilot studies.  

Conclusions: These results strongly support the efficacy of PT as a stand-alone treatment in young children with ASD and disruptive behavior. Future analysis will examine adaptive behavior outcomes and moderators of treatment.