What is already known on this topic

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterised by impaired social communication and restricted/repetitive behaviours.1 Although arguably less cited, delayed adaptive functioning and disruptive behaviours are also considered hallmark features of this disorder. Parent training (PT) is a common treatment for youth with ASD, with previous research demonstrating reduced disruptive behaviour in young children.2 However, the extent to which PT positively influences adaptive behaviour has yet to be investigated.

Methods of the study

The current study examines the immediate and long-term impact of PT, in comparison to an active treatment control on the daily living skills of young children with ASD. Participants included 180 children with ASD aged 3–7 years (158 boys and 22 girls) with at least moderate behaviour problems. Parents were randomised to receive PT or a Parent Education Program (PEP) across six sites. Randomisation was then stratified by high and low educational intensity in school programmes across conditions.

Treatment in the PT condition consisted of 24-weeks in which parents participated in 11–13 PT sessions, two telephone booster sessions, and two home visits. Parents were taught to identify the function, antecedent, and consequences of behaviours. Treatment in the PEP condition included twelve 60–90 min individually administered sessions and one home visit over 24 weeks. Lessons focused on psychoeducation about autism, but did not include behavioural management strategies. In order to measure changes in daily living skills, treatment outcome was assessed using the Vineland Adaptive Behavior Scale-II and the Clinical Global Impression-Severity scale (CGI-S).

What this paper adds

• This paper appears to be the largest randomised trial examining the impact of PT on the daily living skills of youth with ASD.

• The study reveals a significant improvement in Daily Living scores on the Vineland-II for the PT group from baseline to 24 weeks (p=0.004; effect size=0.36) compared with no change in the PEP condition. For children with an intelligence quotient (IQ) <70 in the PT group, analyses revealed less improvement in all three domains of the Vineland-II, with no significant difference relative to IQ in the PEP condition. However, there was a significant difference across conditions within the Daily Living domain for children with an IQ>70, suggesting these youth improved to a greater extent in the PT group and declined slightly in the PEP condition.

• Additional examination of Vineland-II Daily Living subscales revealed a significant improvement in the Domestic and Community subdomains. With regard to clinical global ratings, children who were rated ‘much improved’ or ‘very much improved’ by independent evaluators on the CGI showed greater gains at 24-weeks across all three Vineland-II adaptive skills domains, with only the Daily Living domain approaching significance (effect size=0.38). Finally, long-term treatment effects of PT on Vineland II outcomes reveal maintained improvements from 24 to 48 weeks.

• Results demonstrate that disruptive behaviour may hinder the acquisition of daily living skills in children with ASD, but with targeted PT to decrease disruptive behaviour, improvements in daily living skills may be observed.

• Findings further suggest that children with ASD have lower adaptive functioning than predicted by IQ, and while PT may improve adaptive daily living skills among children with an IQ>70, these gains are seen to a lesser extent in youth with intellectual disabilities.

Limitations

• One limitation of the current study was that the majority of the sample consisted of children with IQ>70. Consequently, these findings may not generalise to a larger population, and may compromise the finding that youth with intellectual disabilities made fewer gains.

• Another limitation is that parents, who provided ratings of adaptive functioning, were not blind to the treatment conditions, which may have biased the results.

What next in research

The current study examined immediate and long-term treatment outcomes following a PT intervention for young children with ASD. Future research might examine the maintenance and trajectory of these outcomes beyond 6 months, along with the impact on independent living skills for older transitional youth with ASD. Given the modest benefit of PT among children with lower cognitive abilities, future research might also examine the benefit of prolonged and more targeted intervention for youth with ASD and intellectual disabilities.

Do these results change your practices and why?

Yes. Results of the current study suggest that disruptive behaviour may hinder the acquisition of daily living skills for youth with ASD. Daily living skills are fundamental to independent living skills, which are often impaired in individuals with ASD. One important implication of this study is the discovery that PT targeting decreased disruptive behaviour appears to increase daily living skills, which may in turn improve adaptive independent living skills in youth with ASD. These findings are encouraging and warrant further investigation.