Some NHS centers are diagnosing twice as many adults as autistic, research shows

Adults waiting for an autism diagnosis face a postcode lottery in England, with some NHS centers more than twice as likely as others to give a positive assessment of the condition.

Groundbreaking research from University College London (UCL) suggests that people in some centers have an 85% chance of being diagnosed as autistic, compared to a 35% chance in others.

The findings from the Improving Adult Autism Assessment study have not yet been peer-reviewed, but have already been picked up by NHS England for further research.

William Mandy, professor of neurological disorders at UCL, who led the research at several NHS trusts in southern England, said the wide variation suggested a lack of consistency between centres. He said it raised fears that lives could be seriously affected by inaccurate diagnoses and called for “radical changes” to the system.

“Our results worryingly suggest that people are being overdiagnosed in some areas and underdiagnosed in others,” says Mandy.

The study looked at a number of possible reasons behind the variation. But, he said, his conclusion was that “someone could go to an established clinic and get one answer to the question of whether he or she is autistic, and then go to another established clinic and get a completely different answer.” , despite showing the exact same thing. behavioral characteristics”.

“The fact is that the diagnostic manuals are open to a lot of interpretation and so there is fundamentally a lack of consensus about where the appropriate boundaries of autism lie,” he added.

Dr. James Cusack, the chief executive of Autistica, Britain’s largest autism research charity, said Mandy’s results did not surprise him. “Diagnosing autism can be a wild west when it comes to inconsistencies in approach,” he said. “We know of many good quality assessment centers where people are not accessing the correct autism diagnoses because that center follows untested diagnostic practices, sometimes even ones that they have developed themselves.”

Cusack suggested the research showed people were being overdiagnosed and said that “unless something is done to regulate this, it will erode public confidence in diagnosis itself”.

He also said there were large regional differences in diagnoses. He pointed to research showing that in some areas up to 4% of children aged 10 to 14 are diagnosed, compared to 1.5% in other areas.

“That is really dangerous because it means there is no clarity about what a diagnosis is for, who it is for and how systems support the wide range of people who receive a positive diagnosis,” he said.

In contrast to Cusack, Mandy suspects that there is more underdiagnosis than overdiagnosis in adults. “But the most important question is: ‘Which level of diagnosis is correct?’ and the honest answer is that no one knows,” he said. “But the fact that there is no consistent conversion rate between referrals and diagnoses is very troubling.”

Mandy said his results “show that we need radical changes in the way autism diagnoses are given”. He said: “Our findings concern me because this is a high-stakes assessment that has great importance in influencing a person’s identity, their access to services and funds, and their life decisions.”

That of the government 2010 autism strategy recommended the creation of specialized, community-based, multidisciplinary teams to deliver, coordinate and oversee services. However, there are no guidelines for staffing these teams or how they should operate. As a result, a number of different models have emerged.

Bryony Beresford, a professor at York University, led the first national one Evaluation of specialized autism team service models in 2020. She also found wide variation in reported diagnosis rates, ranging from less than 50% to more than 80%.

“Each team differed in their diagnostic assessment protocols and each was unique,” ​​she said. “Furthermore, unlike some diagnoses, clinical judgment is central to the diagnostic process of autism and this will contribute to variation. Does this mean we can’t trust diagnoses? We just don’t have the evidence yet to say yes or no to that question.”

Dr. Peter Carpenter, chairman of the Special Interest Group Neurodevelopmental Psychiatryagreed that it was “very much in the eye of the physician-viewer whether someone is diagnosed as autistic or not.”

He said a national agreement on common practices and thresholds was needed, but that some degree of variation was inevitable. “How do you arrive at a definition of autism that experts can work on accurately and consistently, that includes everyone at all ages and includes Mensa members as well as the most profoundly intellectually disabled?” he asked. “All our criteria leave a lot of room for interpretation by individual doctors.”

Many are now turning to independent diagnostic assessments, but the National Autistic Society (NAS) said their decisions could not necessarily be relied on either. “There are a lot of providers now, some for-profit and some not-for-profit,” says Dr. Sarah Lister, clinical director of NAS. “Some are regulated – many are commissioned by the NHS to deal with NHS waiting lists – but some operate with minimal regulation or supervision, so quality is variable.”

An NHS spokesperson said: “The NHS is fully committed to supporting and improving the lives of autistic people, and has published new national guidance for autism assessment services to ensure local areas can meet the 50% increase in referrals they are making. over the past year, being able to process it and at the same time ensure people get the support they need while they wait for assessment.”