Authors: Maathu Ranjan1 and Robert Breunig1
Affiliations:
1Crawford School of Public Policy, Australian National University
Summary:
Worldwide, reported autism prevalence has been increasing rapidly, particularly over the last decade. Australian estimates of autism prevalence are some of the highest in the world and are rising faster than in other countries with comparable economic and health profiles. So, what is driving this phenomenon?
Considerable controversy surrounds the causes of this trend, with researchers pointing to changes in diagnostic criteria and practices, increased awareness of autism and neurodiversity, genetic and environmental factors, and the availability of government funding for support. While many of these factors have impacted global increases in autism prevalence, changes in public policy over the past decade, with the introduction of the National Disability Insurance Scheme (NDIS), are unique to the Australian context.
We find compelling evidence that the introduction of the NDIS and the subsequent shift in the disability support system have increased rates of autism diagnoses in Australia, with significantly faster growth in regions where the NDIS was introduced earlier. We estimate that the shift in disability systems accounts for 47% of the increase in reported autism prevalence since 2012, with the remaining increase attributed to other factors impacting global increases in prevalence.
This result remains significant even after accounting for other possible factors, including gender, household income, education, remoteness, and measures of socio-economic advantage and disadvantage. These factors act as proxies for access to information about autism, cultural attitudes towards disability, and availability of diagnostic services.
Disability advocates attribute these rises in prevalence to the recognition of previously under-reported autism, particularly in younger children. However, we find that the introduction of the NDIS has not resulted in a decrease in age at diagnoses. Further, our analysis also points to a shift in the way that autism is diagnosed in Australia as the NDIS has rolled out. Despite significant growth in overall diagnosis rates, growth in diagnoses from psychiatrists and paediatricians who are subsidised by the national public health system has decreased. This suggests that a new business model for the provision of diagnostic services through private markets has emerged in response to the NDIS.
The provision of quality disability support that achieves sustainable outcomes for individuals is a worldwide policy dilemma. Our results provide evidence that individualised funding models encourage formal diagnoses of autism.
Source: Photo by LIGHTFIELD STUDIOS
