GPs should be given stronger guidance about how to diagnose autism to prevent “doctor shopping” by desperate families trying to access funding for their children that is tied to a medical definition, researchers say.
New, nationally consistent guidelines that crack down on fluid interpretations of the international Diagnostic and Statistical Manual (DSM-V) — the global yardstick for identifying a suite of mental disorders — would push down prevalence rates, which have been climbing dramatically in Australia for years.
The number of those diagnosed with autism in Australia almost doubled between 2003-06 and has doubled every three years since, hitting 115,000 in 2012 and likely to top 230,000 in 2015 when survey data is finalised.
University of Western Australia child development expert Andrew Whitehouse told The Australian: “Without a doubt the bulk of the increase in autism cases is due to shifting diagnostic boundaries over time. This has been a human-imposed change rather than a biological change over time. That is not to discount the fact there may be a new cause in the modern environment but there has been a wealth of research into this and we have not found another factor yet.”
The Australian spoke to multiple academics who confirmed a stricter diagnostic regime applied across the country would remove some of the wriggle-room medicos have to fudge diagnoses and eliminate confusion.
Professor Whitehouse, who is also a program director at the Autism Co-operative Research Centre, said every state and territory adhered to the DSM-V but the manual set out only broad categories of behaviours. Actual diagnoses “varied wildly between states”.
“At the moment what we call autism — or at least autism concepts — differs wildly between those states and that absolutely has an effect on prevalence rates,” he said.
“I have heard numerous stories over many years of families being able to go to a single sole practitioner and receive a diagnosis of autism without an extensive assessment. Moreover, if you don’t get the diagnosis you need then you can go to another and another and another.
“Once you tighten up those diagnostic procedures, it just has to have an effect on numbers.”
Professor Whitehouse said parents did not automatically want to have their children diagnosed but government funding programs that linked diagnoses with funding created a perverse incentive for cash-strapped families who wanted to access early-intervention services.
Cheryl Dissanayake, director of the Olga Tennison Autism Research Centre at La Trobe University, told The Australian the number of people diagnosed was “flexible” and largely in the hands of people on the frontline.
Professor Dissanayake and colleagues examined data from a federal government support program and found three times as many children aged under five were enrolled in the federal government’s Helping Children with Autism package than anticipated.
The Productivity Commission tried to reckon with rising autism rates as it built the framework for the $22 billion National Disability Insurance Scheme and said it believed the rise in diagnoses was at least partly linked to the HCWA program, which had to be propped up with another $30 million in funding after its popularity.
Professor Dissanayake was part of a working party which, in 2009, recommended the Victorian government copy the “best practice” diagnosis model operating in Western Australia which requires a paediatrician, speech pathologist and child psychologist to agree on an outcome.
“That was adopted in Victoria but it was mandated and there is a big difference between requiring best practice and simply recommending it,” Professor Dissanayake said.
“That is the real issue.”
The last official data in Australia shows Victoria had far and above the highest rate of autism, about 0.7 per cent compared with slightly more than 0.5 per cent for the closest other state, Tasmania.
Nationally, there is also a slow shift in education departments away from requiring labels before releasing funding to students and schools, a model that led the rate of autism in Queensland public schools to hit one in 50 in 2010 when the global rate was much closer to one in 160.
A spokesman for Victoria’s Education Minister, James Merlino, said a review of disability support programs was finished and the findings were expected to be presented to the government within months.
In NSW, the state government broadened support for students with disability by paying a loading to students without the requirement of a formal diagnosis.
About $63m has been allocated to schools this year to support those efforts.
Queensland is moving toward needs-based funding while South Australia’s Education Minister, Susan Close, said diagnoses could still be useful.
“While specific support for students with disabilities requires a professional diagnosis, in SA there is also support for a range of learning difficulties that is based on what individual children need to be successful, and does not require formal diagnosis of disability,” Ms Close said.
Australian Medical Association president Brian Owler said that having “consistent guidelines would make things easier” for doctors during diagnosis but added the emphasis should still be on assessing children early.
“It is probably harder early on to make the diagnosis, harder to make a firm diagnosis but at the end of the day, if early therapy is instituted and a child is found later on to not have autism that is a good thing,” Dr Owler said.
Professor Whitehouse said greater thought needed to be given to the range of support provided in the early years and during school years.
“We have to think about what those programs look like,” he said.
“The mark of a civilised society is how it treats its most disadvantaged. There are families crying out for help, a great big population of them.”