CHAT screening test

The CHAT (Checklist for Autism in Toddlers) screening test is often carried out by a GP, health visitor or member of an autism team in order to detect a spectrum disorder.

It is carried out on pre-school children aged 18 months who are due for a developmental check up. The aim is to see if the child is displaying any signs of a developmental disorder such as autism.

There is a similar screening test for adults which have the same aims.

What does CHAT involve?

It consists of a questionnaire which is completed by the health worker/GP and parents. The first section contains a series of questions which the parents answer: the second section is based on observations made by the health worker/GP.

The parents answer 9 questions.

The health worker completes 5 observations of the child’s behaviour.

Example question (for parents):

"Does your child take an interest in other children?"

Example of an observation by the GP/health worker:

"Can the child build a tower of bricks and if so, how many?"

Aims of CHAT

The aim is to see if the child is unable to demonstrate a series of motor skills and behaviours which would normally be expected at that stage in their development. Children acquire skills from birth up to 3 years or more in a progressive manner which means these skills become more complex the older they get.

A child would normally have acquired a set of physical, psychological and social skills by the age of 18 months. Examples of these include:

• Crawling and walking/running
• Basic vocabulary
• Be able to play with other children or at least take an interest.

A child should be able to point towards an object or look at what their parent is pointing at, e.g. a toy. But if the child fails to display these skills then it indicates a delay in their development which may be a sign of a spectrum disorder.

Analysing CHAT

This questionnaire has a simple scoring system which is as follows:

• A5: ’pretend play/role playing’
• A7: ’protodeclarative pointing’
• Bii: ’following a point’ (when an adult points to something)
• Biii: ’pretending’
• Biv: ’producing a point’ (the child is able to point towards something).

If a child fails A7 and Biv then they have a moderate chance of developing autism. But if a child fails all 5 of these items then they are at a high risk of developing autism.

(Source: The National Autistic Society/screening and diagnosis)

Passing the CHAT

If your child passes the CHAT then no further tests will be done. But, this does not always mean that the child will not develop a spectrum disorder at some stage. So, it may be worthwhile undergoing another CHAT screening at a later date or a similar test.

Failing the CHAT

If your child fails the CHAT then he/she will undergo another screening a month later. This is not a confirmation of diagnosis: rather it is designed to see if your child is a ’late developer’who will catch up a bit later than many others.

Plus it is useful to monitor the progress of a child who has failed several developmental stages. It is not a diagnostic tool so further tests will be required.

Your child will undergo additional tests at a specialist clinic.

Advantages of CHAT

This is a simple, low cost and effective method for detecting behavioural problems such as autism. Bear in mind that autism is one of several disorders on the autism spectrum so more than one test is required for a diagnosis.

Another advantage is that it detects any problems at 18 months old which is when any problems are likely to arise. An autistic spectrum disorder occurs before the age of 3 so is likely to be detected using this method at the age of 18 months.

Are there any disadvantages of CHAT?

This is a well known and established test to screen for autistic spectrum disorders. It is used in conjunction with other tests as part of a multi-disciplinary approach to autism.

It appears to be a quick and efficient way of detecting any developmental problems so no disadvantages as far as we can see.