Mapping the Diagnosis of Autism Spectrum Disorders By Age 7 in Australia: 2010 – 2012

Background: The early diagnosis of young children with Autism Spectrum Disorder (ASD) is critical to ensure access to early intervention services. ASD can be accurately and reliably diagnosed by 24 months; however, diagnosis often does not occur until a later age.

Objectives: The frequency and age of diagnosis (AoD) of ASD in children, under 7 years, living in Australia was investigated to examine trends across states, metropolitan, regional and remote areas and the child characteristics of sex, diagnosis type, Indigenous, and cultural minority group status.

Methods: Secondary de-identified data regarding 15,096 children aged 0 – 7 years registered through the national Helping Children with Autism Package between 2010 and 2012 were utilised.  ASD diagnoses consistent with the DSM-IV were confirmed by a pediatrician, psychiatrist or multidisciplinary team assessment.  The number of cases by state was calculated and compared to the estimated population of children in the specified age range.

Results: On the basis of this data, 0.74% of the population of children aged 0‐7 in Australia are currently diagnosed with ASD. The average age of diagnosis of ASD (by age 7 years) was 49 months, with the most frequently reported diagnostic age being 71 months.  Differences were evident in the frequency of ASD and average AoD across states (see Figure 1) and between major cities, regional and remote areas.  There was no difference in AoD between Indigenous and non-Indigenous Australians, but children from a culturally and linguistically diverse background were diagnosed 5 months earlier than other children. 

Conclusions: The current AoD of ASD in Australia indicates a substantial gap between the age at which a reliable and accurate diagnosis is possible, and the age at which most Australian children are diagnosed with ASD.  Findings suggest that the frequency of ASD in Australia has increased substantially from previous estimates.