24859
Using Health, Education and Research Administrative Databases to Better Understand Autism Prevalence in Australia
Autism Spectrum Disorder (ASD) prevalence has been increasing worldwide. In Australia varied prevalence estimates have been reported from under 1% to more recently 2.5%. Exploring different administrative and research databases with varied criteria for the classification of ASD may provide insight into factors influencing prevalence.
Objectives:
To explore the prevalence of ASD in Australia using research and administrative databases from health, education and research systems using data collected in 2014.
Methods:
Secondary analyses of health, education and research databases were performed. The Victorian Department of Education and Training program for students with disability data was used to explore ASD prevalence in school aged children (5-18 years). To be classified under the ASD category, in addition to a confirmed medical diagnosis of ASD, children required a severe language impairment. Health data from the Australian Medicare Benefits Scheme items used by paediatricians and psychiatrists for the diagnosis of children with ASD aged 0-12 years was also explored. This required a paediatrician or child psychiatrist confirmed ASD diagnosis. Secondary analysis of the Longitudinal Study of Australian Children (LSAC) were also performed. LSAC is a nationally representative sample of Australian children. Parent reported ASD diagnoses from the Birth cohort (born in 2003/2004) collected in 2014 when the children were aged 10-11 years were used. Medicare ASD diagnostic items linked to LSAC data were also explored.
Results:
Education data showed the prevalence of ASD in the Victorian state school aged population (5-18 years) was 0.87% (95% CI 0.84-0.89). Health data using Medicare diagnostic items showed a preliminary prevalence of 2.81% (95% CI 2.80-2.83) in children aged 0-12 years. The parent reported prevalence of ASD diagnoses in 2014 using LSAC research data from the Birth cohort was 3.86% (95% CI 3.17-4.55) in 10-11 year old children. Medicare linked ASD diagnostic items in the LSAC Birth cohort were lower than parent report at 1.73% (95% CI 1.36-2.21).
Conclusions: No one administrative source will present a complete picture of service need and administrative sources are often thought to underestimate true prevalence. Large differences in prevalence depending on the data source were not expected nor were higher prevalence estimates than have been reported in other study designs and settings. Factors driving high estimates and differences need to be understood, as does appropriateness of service access.