NHS Autism Report suggests the increase in autism in recent years was all down to an oversight …
Polly Tommey is the mother of a thirteen year old son with autism.She is also the Editor of www.autismfile.com. In both roles, as a mother speaking with other parents day in, day out, and as a journalist dealing withconstantly increasing numbers of calls describing personal crises for the lastten years, she has had direct experience of the increasing pressure being causedby the numbers of people dealing with autism.
Polly, like many others, has also attended conferences, seminars and workshopsworldwide for the last decade and has heard endless research reports and debates on what is the cause of the increase in the prevalence of autism in countriesacross the world.Statistics citing 5 in 10,000 with autism in 1990 increasing to 1 in 100 today have been used bymany from all backgrounds. However it ‘appears’ that it was all now a mistake and that there has been no increase at all … the apparent 95% step up was simply down to an oversight, a lack of awareness and non-diagnosis.Autism isn’t a new problem at all, we’ve had the same level all along – and perhaps, if the data is critiqued, it is actually in decline!
Scepticism surrounds the interpretation of this new report … “Why on earth did this ‘ground-breaking’ news get forced up the news bulletins in the way that it did on Monday evening here in the UK?”, asks Polly, “Are we really able to believe all that we hear on such important subjects, or is there a stronger hand with adifferent agenda behind it?”
A review of the detail behind the headlines will enable any objective reader to draw their own conclusions …
According to a National Health Service report published yesterday (Sept 22nd) 1 in 100 adults in theUK has an Autism Spectrum Disorder (ASD). The report was based on adults living in households throughout England and the assessments were done in two stages. Stage One asked individuals to rate how well they agreed with 20 statements about their likes, dislikes and abilities – such as whether they preferred going to ‘libraries’ or ‘parties’. Stage Two involved a clinical interview designed for adolescents and adults with fluent speech. No-one in thestudy lived in supported accommodation or residential care; everyone in thestudy was verbally fluent. Nonetheless, 1 in 100 had an Autism Spectrum Disorder?
Subsequent news reports are claiming that these figures match the numbers already identified in children, however the children’s figure includes less able, less fluent and non-verbal children. If the full range of ability had been included in the NHS report, alongside the verbally fluent, high functioning adults living at home, there would surely be far more than 1 in 100. So, either there are more adults than children with an ASD and autism is on the decline(!?) or there is something wrong with the report.
Polly comments, “The irony for many families in the UK is that in order to get support for a child with an ASD you have to wait over two years for a diagnosis; if you wait long enough, eventually you will be asked to spend several hours talking in detail about your child’s development, his present behaviour, his speech,language and cognitive ability. You will need to have your child observed athome, at school, in the playground, in the classroom, and then you will need tostart the long process of applying for a Statement of Educational Need to makesure he gets the educational provision he needs. If this fails, which it oftendoes first time around, you will need to do it again, maybe with legalrepresentation, and a significant hole in the bank balance.”
Polly cynically concludes, “So, perhaps the report is good news. Maybe now, ASD diagnosis will be based on a few questions about whether you like ‘libraries’or ‘parties’ best, followed by a 30 minute chat. One thing is clear, however, the report has no relevance to children withautism like my son Billy and the many thousands like him. These are children who the system has so far failed and who, unless something is done now, certainlywon’t be coping as adults, in ordinary ‘English households’, or responding to self-report questionnaires about their social nuances.”
Dr Carol Stott, Scientific Editor of The Autism File Magazine comments on thereport:
Whatever claims are made to the contrary this report tells us very little about the number of adults with ASDs – inEnglandor anywhere else. The main problems with the study are with (a) case-definition, (b) ascertainment (c) diagnostic instruments (d) case identification and (e) statistical power.
There is no clearly stated case-definition anywhere in the report. The cases reported are defined loosely in terms of an initial score on a shortened unstandardised non-peer reviewed version of ascreening tool together with a semi-structured clinical interview – the Autism Diagnostic Observation Schedule (ADOS) – that was not designed to act as astand-alone diagnostic instrument.
The sample selected is not representative of the ASD population. All participants were verbally fluent, living in ordinary households, and able to complete a self-report questionnaire.
The choice of measurement tools is inadequately justified and badly referenced. No details are provided, nor are any sources referenced, on the psychometric properties of the initial screening instrument (AQ-20). The standardized scoring criteria for the ADOS were not followed (using a total cut-off of 10 for Communication + Social Reciprocity, rather than three cut-offs (respectively) of 3, 6 and 10 for Communication, Social Reciprocity and the two combined). Additionally the authors over state the validity of the ADOS as a tool for use in adult populations. Module Four (used in the study) was standardized on a sample of only 70 adults aged between 16 and 44. Ages in the study sample range from 16 – 75.
The technical appendix, which is intended to provide information about the derivation of the AQ-20 is statistically naïve, unclear and potentially inaccurate. It is not clear for example, what is meant by the phrase on pg 16 of Appendix C "….once the final set of predictors had been selected, a regression equation was available for predicting the prevalence of ADOS." Neither is it clear whether General Linear Modelling, Linear Regression or both were used to derive final items.
Finally, inferences are made about the lack of a significant association between age-groups and ASD prevalence without reference to statistical power. In a study of this size, with only 19 identified (unweighted) cases, the likelihood is that the study was underpowered to detect such differences.
A valid and reliable study of the population frequency of a disorder requires clear and robust case definition, validated instruments, standardized procedures and adequate statistical power. An initial evaluation of this report suggests it fails on all counts. A further much more detailed critique is currently being prepared and will be featured in The Autism File Magazine: Scientific Review early in the New Year.