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Age at Diagnosis of Autism Spectrum Disorders in Four Regions of Canada

  • Quantitative Research
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Abstract

Objectives: Early diagnosis of autism spectrum disorders (“autism”) may lead to better treatment outcomes, reduces the stress parents experience when they do not understand the reasons for their child’s behaviour, and empowers parents to make choices such as seeking genetic counseling. We examined the age at which Canadian children are diagnosed with autism, and analyzed whether there are geographic or temporal variations or differences by sex or diagnostic subtype.

Methods: As part of an autism surveillance program, in 2002/2003 we began collecting information on children with autism in Manitoba, Southeastern Ontario, Prince Edward Island, and Newfoundland and Labrador. For the analysis presented in this paper, we included children identified for our surveillance program who were diagnosed between 1997 and 2005 (n=769).

Results: We found significant inter-regional differences in age at diagnosis, with Newfoundland and Labrador having the lowest median age at diagnosis (39.0 months) and Southeastern Ontario the highest (55.0 months). Diagnostic subtype was significantly associated with age at diagnosis in all regions. Southeastern Ontario was the only region where the overall age at diagnosis increased over time (p=0.004), although in Manitoba the age at which children were diagnosed with PDD-NOS also increased significantly over the study period (p=0.021).

Conclusions: Our findings demonstrate that there are geographic differences and other sources of variation in the age at which Canadian children are diagnosed with autism. Further study is warranted to understand the factors contributing to these differences. Such research would inform best practices for early detection and timely access to treatment.

Résumé

Objectifs: Le diagnostic précoce des troubles du spectre autistique («autisme») peut mener à de meilleurs résultats de traitement, réduire le stress que vivent les parents lorsqu’ils ne sont pas en mesure de comprendre les raisons du comportement de leur enfant et habiliter les parents à prendre des décisions, comme recourir à la consultation génétique. Nous avons examiné l’âge auquel les enfants canadiens ont reçu un diagnostic d’autisme et avons analysé s’il y avait des variations géographiques ou temporelles ou encore des différences selon le sexe ou le sous-type de diagnostic.

Méthodes: En 2002-2003, nous avons entrepris, dans le cadre d’un programme de surveillance de l’autisme, la collecte de données sur des enfants atteints d’autisme au Manitoba, dans le sud-est de l’Ontario, à l’Île-du-Prince-Édouard et à Terre Neuve-et-Labrador. En ce qui concerne l’analyse présentée dans ce document, nous avons inclus les enfants, identifiés dans le cadre de notre programme de surveillance, ayant reçu un diagnostic entre 1997 et 2005 (n=769).

Résultats: Nous avons observé des différences importantes entre les régions sur le plan de l’âge au moment du diagnostic; Terre-Neuve-et-Labrador présentait l’âge moyen au moment du diagnostic le moins élevé (39,0 mois) et le sud-est de l’Ontario le plus élevé (55,0 mois). Le sous-type de diagnostic était fortement associé à l’âge au moment du diagnostic dans toutes les régions. Le sud-est de l’Ontario était la seule région où l’âge global au moment du diagnostic augmentait avec le temps (p=0,004), bien qu’au Manitoba, l’âge auquel les enfants reçoivent un diagnostic de TED-NS ait aussi augmenté considérablement au cours de la période à l’étude (p=0,021).

Conclusions: Nos conclusions démontrent qu’il existe des différences géographiques et d’autres sources de variation dans l’âge auquel les enfants canadiens reçoivent un diagnostic d’autisme. D’autres études s’avèrent nécessaires pour comprendre les facteurs qui contribuent à ces différences. Ces recherches permettraient de mieux documenter les meilleures pratiques concernant la détection précoce et l’accès rapide au traitement.

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Authors and Affiliations

  1. Department of Community Health and Epidemiology, Queen’s University, 191 Portsmouth Avenue, Kingston, ON, K7M 8A6, Canada

    Hélène M. J. Ouellette-Kuntz MSc (Associate Professor), Helen Coo MSc (Research Associate) & Miu Lam PhD (Associate Professor)

  2. Department of Psychology, University of Manitoba, Winnipeg, MB, Canada

    C. T. Yu PhD (Associate Professor)

  3. Department of Education and Early Childhood Development, Charlottetown, PE, Canada

    Marlene M. Breitenbach MSEd (Special Education Autism Coordinator)

  4. Department of Health & Community Services, Intervention Services & Autism, St. John’s, NL, Canada

    Paula E. Hennessey BA (Provincial Consultant)

  5. Department of Psychiatry, Queen’s University, Kingston, ON, Canada

    Jeanette J. A. Holden PhD (Professor)

  6. Department of Community Health and Epidemiology, Queen’s University, Kingston, ON, Canada

    Hilary K. Brown BA (Research Assistant)

  7. Department of Social Services and Seniors, Charlottetown, PE, Canada

    Andrea L. Noonan MA (Early Intervention Coordinator)

  8. Department of Education, St. John’s, NL, Canada

    Robert B. Gauthier MEd, MSc (Professional Development Consultant) & Lori R. Crews MSEd (Professional Development Consultant)

Authors
  1. Hélène M. J. Ouellette-Kuntz MSc
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  2. Helen Coo MSc
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  3. Miu Lam PhD
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  4. C. T. Yu PhD
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  5. Marlene M. Breitenbach MSEd
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  6. Paula E. Hennessey BA
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  7. Jeanette J. A. Holden PhD
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  8. Hilary K. Brown BA
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  9. Andrea L. Noonan MA
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  10. Robert B. Gauthier MEd, MSc
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  11. Lori R. Crews MSEd
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Corresponding author

Correspondence to Hélène M. J. Ouellette-Kuntz MSc.

Additional information

Acknowledgements: This work was supported by an Interdisciplinary Health Research Team Grant from the Canadian Institutes of Health Research (#43820) to the Autism Spectrum Disorders Canadian-American Research Consortium (ASD-CARC) (J.J.A. Holden, Principal Investigator) and an Operating Grant from the Canadian Institutes of Health Research (#79556) to H. Ouellette-Kuntz.

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Ouellette-Kuntz, H.M.J., Coo, H., Lam, M. et al. Age at Diagnosis of Autism Spectrum Disorders in Four Regions of Canada. Can J Public Health 100, 268–273 (2009). https://doi.org/10.1007/BF03403945

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  • DOI: https://doi.org/10.1007/BF03403945

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