Behavioural Interventions for Preschool Children with Autism
Autism is a neurobehavioral syndrome characterized by deficits in reciprocal social interaction, impaired reciprocal verbal and nonverbal communication, and restricted and repetitive patterns of behaviour, interests and activities. An increasing number of Canadian families are requesting assistance in obtaining therapies for children with autism. This may be attributable to many factors ranging from an actual change in incidence, an increase in prevalence, greater awareness, changes in diagnostic criteria, the development of instruments to aid diagnosis and assessment, insufficient resources to meet the needs of children and families, and/or an increased number of informed parents with a desire to improve the outcome for a child with an autism-related condition.
The objectives of this study are to present a summary of evidence and expert opinions regarding behavioural therapy, and describe Canadian issues and initiatives, an analysis of legal case findings in the area, and key factors that influence the provision of services to preschool children with autism in Canada.
This report does not purport to be a critical appraisal of primary studies but is a systematic review of the literature which summarizes recent reviews and expert opinions regarding behavioural therapy.
Specific questions addressed in this review are:
- What is the evidence and expert opinion of respected authorities regarding behavioural therapies and outcomes in preschool children with autism or pervasive developmental disorders based on available research and clinical experience?
- What is the current practice regarding behavioural therapy for preschool children with autism or pervasive developmental disorders in Canada?
- What legal cases related to treatment for autism have occurred or are pending in Canada? What legal cases have occurred outside of Canada?
- What factors influence the delivery of services to children with autism in Canada?
Published literature was obtained by searching a number of databases. These searches were supplemented by hand searching and searching the Internet. Information regarding current service provision and Canadian initiatives was based on contacts identified in a survey previously commissioned by the British Columbia Ministry for Children and Families, and discussions with contacts formed as a result of research forum discussions with the Canadian Autism Intervention Research Network (CAIRN).
Based on the secondary reviews evaluated in this report, there are few published controlled primary studies regarding the efficacy of behavioural interventions; most have methodological flaws that make interpretation of results difficult. Study design in this area could benefit from the inclusion of an adequate control group and the application of consistent outcome measures used for all children enrolled in a study, administered by the same, blinded assessor at the beginning and end of the study. There are some systematic reviews that largely concur in their conclusions. Existing evidence suggests that behavioural intervention, including a minimum intensity of approximately 20 hours per week of one-to-one applied behavioural analysis, can improve aspects of function, in particular performance on IQ tests, in children with autism. However, it is not possible to define the sufficient number of hours per week of intervention that are required for a positive outcome. There is little guidance regarding cessation or modulation of the level of intensity for behavioural therapy. Within the last two years, many provinces in Canada have initiated pilot projects to deliver behavioural intervention to children with autism. These projects are based on behavioural strategies whose characteristics have demonstrated some success.
Canadian judgments in legal cases of parents claiming appropriate treatment for autistic children have not yet reached a level constituting legal precedent in any province. In a legal case in British Columbia, where parents sought funding for therapy for children with autism, a proposed model of early intervention was accepted as an effective treatment for autism spectrum disorder for children below six years of age. Decisions made in other jurisdictions offer little guidance on how Canadian courts of authority are likely to resolve claims for provincial funding of services.
The delivery of services to children with autism has been influenced by the introduction of universal healthcare to Canada, the shift to community-based programming and integration, as well as the evolution of the classification system for diagnosis.
Discussion and Conclusion
Though limited, findings of existing studies suggest that preschool children with autism exhibit cognitive and functional improvement when receiving behavioural intervention with applied behavioural analysis for approximately 20 hours per week or more. It is not clear, however, which subset of children with autism derive the most benefit, which components of therapy are integral to positive outcomes, whether similar results would be observed in older children with autism, whether there are definable long term functional benefits, or whether reported gains in IQ translate into happier people with greater functioning in the community.
It is important for policy makers, program developers and clinical researchers to consider identifying pre-treatment characteristics of those receiving therapy, measuring treatment fidelity, evaluating progress in therapy to determine whether therapy is or continues to be of benefit, and comparing the value of early intensive behavioural therapy to other early interventions for autism.
Methodological flaws in the primary studies that were examined in reviews suggest that standard measures for assessment, continued evaluation of progress, and long term functional outcomes are required in future study design. Improved research methods would provide more reliable evidence about therapeutic effectiveness and would assist in the planning of individualized treatment programs aimed at more successful outcomes.