Understanding the Diagnostic Process of Autism Spectrum Disorders: What Methods Are Used and Who Is Making Diagnoses?

Background: In Canada, Autism Spectrum Disorders (ASDs) are diagnosed by a variety of health care providers, including psychologists, family doctors, developmental pediatricians, and psychiatrists. Gold standards and best practices for the assessment and diagnosis of ASDs have been outlined by several organizations and professionals (e.g. Filipek et al., 1999; Johnson et al., 2007; Ozonoff et al., 2005); however, in practice the assessment methods used often vary depending on the professional designation, assessment setting (e.g. hospital, private practice, and school), and client characteristics (e.g. developmental level and age). Given that a comprehensive assessment and accurate diagnosis are integral to the development of appropriate treatment plans (Kabot et al., 2003; Rogers, 1998; Williams, Atkins, Soles, 2009), and to accessing services, it is important to examine the specific assessment methods being utilized to make an ASD diagnosis across health care providers.

Objectives: To gain insight into the experiences of families who have gone through the process of receiving an ASD diagnosis. Specifically, to understand which health care professionals are making different ASD diagnoses (i.e. Autism, Asperger, Pervasive Developmental Disorder-not otherwise specified), the measures they are using to make these diagnoses, and the age that children are being diagnosed. 

Methods: A review of previous diagnostic reports and parent diagnostic history surveys were used in the current study. Trained researchers reviewed the diagnostic reports to code for assessment measures utilized, age of client, health care profession, and diagnosis given.  The parent survey asked parents to report information related to the diagnostic history of their child, such as age of first concern, who referred them to seek a diagnosis, previous diagnoses given, current presence of multiple diagnoses, etc.

Results: Data collection and analysis are near completion. Information from the diagnostic reports, as well as the diagnostic history survey, are being analyzed to identify which heath care providers are more likely to make specific ASD diagnoses, and the age at which these diagnoses are being made. Importantly, the differing assessment measures utilized are being compared across diagnoses, health care providers, and settings.

Conclusions: The results of the study will be important for understanding the assessment processes that are occurring within and between different health care providers, settings, and ASD diagnostic groups.  An examination of the current assessment and diagnostic processes is important for determining if best practices are being used and for identifying gaps within the current mental health system, and what can be done to improve training and access to best practice assessments.