Change over Time in the Age and Number of Children Accessing Autism Specific Funding in Australia

Background:  The early identification and diagnosis of individuals with Autism Spectrum Disorder (ASD) is a critical step in the pathway through to early intervention and support services.  Access to autism specific intervention and funding services is largely dependent on a diagnosis of ASD. Factors found to influence the age that a child is first diagnosed include child and family characteristics (such as cultural background and the severity of symptoms) as well as characteristics specific to the health system and services. Examining trends over time allows us to investigate the influence of changes within the service environment, such as the introduction of the revised diagnostic criteria (DSM-5) in 2013.

Objectives:  The aim of the current study was to examine change over time in the age and number of children diagnosed with ASD and accessing autism specific funding, both prior to and following the introduction of the DSM-5.

Methods:  This study utilised a large administrative data set regarding 32,199 children aged under 7 years who had received a diagnosis of ASD in the community (confirmed by a Pediatrician or multidisciplinary team assessment) and registered to receive autism specific funding through the Helping Children with Autism Package (HCWA) in Australia from January 2010 to June 2015.

Results:  The average age and number of children diagnosed with ASD and registered to receive autism specific funding were both observed to increase over time; with increases in the frequency of diagnoses generally corresponding with a parallel increase in the average age of diagnoses (see Figure 1). The estimated annual incidence of children diagnosed with ASD and registered with HCWA increased from 20 per 10,000 in 2010 to 34.2 per 10,000 in 2013. Following the introduction of the DSM-5 in 2013, the estimated annual incidence of ASD plateaued, with no further significant increase in incidence evident from 2013 to 2015.

Conclusions:  Characteristics of the service environment influence the average age and number of children diagnosed with ASD in a community. The parallel trends of increasing age and frequency of diagnoses observed in this study suggest that an increase in the number of children diagnosed with ASD in Australia has contributed to an increase in demand for diagnostic services, and slightly longer waiting lists. These findings also suggest that the introduction of the comparatively more stringent diagnostic criteria (DSM-5) may have contributed to an attenuation of the trend of increasing diagnoses over time; whereby relatively fewer children have received a diagnosis of ASD and registered to receive autism-specific funding since its introduction.