Children and adults seeking an autism diagnosis in England are up to almost seven times more likely to receive one in some NHS foundation trusts than others, according to research.
Freedom of information requests by the charity Autistica revealed that positive assessments in children ranged from 100% of those evaluated by one trust to just 18% in another. In adults the figures ranged from 97% to 14%.
The findings came from requests to all 42 NHS integrated care boards (ICBs) in England and 120 providers of NHS autism services in March 2024.
The data shows that 100% of children evaluated in Kingston, south-west London, were given positive assessments by Achieving For Children, a social enterprise company.
In Bedfordshire, which is covered by Cambridgeshire community services NHS trust, just 18% of evaluated children were found to be autistic. But in Cambridgeshire, under the same trust, the figure was 44%.
Dr James Cusack, the chief executive of Autistica, said: “What our robust research – the first of its kind – shows is that each integrated care board is taking a different approach to autism diagnoses.
“The huge variation in diagnosis shows that many ICBs are using their own initiatives, some of which don’t involve assessing people’s needs and strengths, without checking if they even work. It’s deeply worrying and raises a multitude of questions and concerns.”
A spokesperson for Achieving For Children said: “Our very high conversion rate is likely to be due to … a neurodevelopmental screening process … which means those waiting for assessment have already met screening criteria. In addition, schools have been very well engaged … which is likely to lead to good referrals.”
Dr Steve Bush, the director of children and young people’s services at the Cambridgeshire trust, said: “Each area commissions services in a different way. The needs of the children referred to us can also vary greatly between areas because there are different types of support available within schools and early help services.”
Cusack stressed that the figures did not necessarily suggest too many diagnoses were being made in areas with high rates, or too few in areas with lower numbers.
“Areas giving the most diagnoses could be under-diagnosing because they’re not referring anyone on who doesn’t have very clear autism,” he said. “Areas that have a low rate could be over-referring because they’re sending too many people for diagnosis.”
Prof Marios Adamou, a consultant psychiatrist at South West Yorkshire partnership NHS foundation trust, said: “There is a lot of idiosyncratic interpretation of autism, depending on how much each service adheres to the NHS’s diagnostic criteria and what each psychiatrist’s own interpretation of what autism is.”
In adults, 97% of those evaluated under Berkshire healthcare NHS foundation trust received a positive assessment while just 14% in Suffolk did so.
The data also reveals variations between adult and child assessments in the same areas. In Suffolk, for example, 89% of evaluated children were positively assessed.
There were also big differences in conversion rates from the same private company working in different areas. One company, Psicon, had a 92.8% positive assessment rate for children in the Surrey Heartlands area, a 71.3% rate in Hampshire and a 64.7% rate in the Isle of Wight. Hampshire and the Isle of Wight are covered by the same NHS foundation trust.
In Surrey, covered by the Kent community health foundation trust, Psicon had an 80% conversion rate for adults, while Sinclair-Strong, a Kent-wide private mental health service, had a 37% positive diagnosis rate.
The government’s 2010 autism strategy recommended the establishment of specialist teams to provide services. But as there is no guidance around the staffing of these teams or how they should operate, a number of different models have emerged.
Tim Nicholls, an assistant director of policy, research and strategy at the National Autistic Society, said: “This extreme variability is unacceptable and evidence the system isn’t working. That is because nowhere has the resources to follow the NHS framework.”
An NHS spokesperson said: “We have published new national guidance to help local partners to deliver high-quality autism assessment services for people in their area and manage the 140% increase in referrals over the last four years, while providing enhanced autism training for psychiatrists.”
