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.
Keywords: Autism, autism spectrum disorders, early identification, age at diagnosis
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.
Mots clés: autisme, troubles du spectre autistique, détection précoce, âge au moment du diagnostic
Footnotes
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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