Checklist for Autism in Toddlers (CHAT)
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Type of Measure: The Checklist for Autism in Toddlers (CHAT) is a screening instrument that identifies children aged 18 to 24 months who are risk for autism. It was devised to test the prediction that those children not exhibiting joint attention and pretend play by the age of eighteen months might be at risk for receiving a later diagnosis of autism. The CHAT takes 5-10 minutes to administer. The first nine questions (section A) are asked of the caregiver by a health practitioner, who then completes the five “key items” in section B through direct observation. The five “key items” are concerned with joint attention (e.g. pointing, eye contact, following gaze) and pretend play (i.e. appropriate use of a teaset, doll play, object substitution), which are then used to cross-check the caregivers’ answers in section A. Those children who fail on all five key items are predicted to be at greatest risk for autism. Other risk categories include: high risk, medium risk, and low risk.
Target Population: Children 18-24 months
Measurement properties and previous use: Baron-Cohen et al. (2000) examined the CHAT’s sensitivity, specificity, and predictive value in a population screening study with 16,235 children aged eighteen months between April 1992 and April 1993. For autism, the high risk criteria of the CHAT had a sensitivity of 18%, specificity of 100%, positive predictive value of 75%, and negative predictive value of 99.7%. For other pervasive developmental disorders (PDD), the medium and high risk criteria combined had a sensitivity of 21.3%, specificity 99.9% and positive predictive values 58.8%.
Baird et al. (2001) further report that in order to minimise false positives a two-stage screening procedure was adopted. Children who were initially screen positive received a second administration of the screen one-month later. Used in this 2 stage way, the positive predictive value of the screening instrument was high (83% for autism and PDD using the highest risk threshold). However, there was poor sensitivity (18%) indicating that four-fifths of the children subsequently identified as showing autistic development in the study population were missed on screening.
If a one-stage screening procedure only had been adopted the proportion of children with autism identified increased to 38%, although in clinical use this would have entailed the assessment of more screen false positives. However, the positive predictive value for identification of all (PDD and non-PDD) developmental problems was 48% (see Baird et al., 2000 for full details). What is clear is that while 9% of the screened population were reported to not produce simple pretend play at age 18 months and 4.5% were reported to not point for interest, failing a combination of joint attention and pretend play items (by both parental report and health practitioner observation, and on both administrations of the screen) indicated a significant risk for developing autism.
Languages: العربية, Française, Deutsch, Estonian, Έλληνες, Latvian, فارسی, Romanian, Spanish, and Svensk
Authors and Citation:
Baird, G., Charman, T., Baron-Cohen, S., Cox, A., Swettenham, J., Wheelwright, S., & Drew, A. (2000). A screening instrument for autism at 18 months of age: a 6-year follow-up study. Journal of the American Academy of Child & Adolescent Psychiatry, 39(6), 694-702.
Baird, G., Charman, T., Cox, A., Baron-Cohen, S., Swettenham, J., Wheelwright, S., & Drew, A. (2001). Screening and surveillance for autism and pervasive developmental disorders. Archives of Disease in Childhood, 84(6), 468-475.
Baron-Cohen, S., Wheelwright, S., Cox, A., Baird, G., Charman, T., Swettenham, J., … & Doehring, P. (2000). Early identification of autism by the CHecklist for Autism in Toddlers (CHAT). Journal of the royal society of medicine, 93(10), 521.
Licence: This measure is freely available online, and may be used along with proper citiation. You are welcome to download these tests provided that they are used for genuine research purposes, and provided due acknowledgement of Autism Research Centre (ARC) as the source is given.
Link to measure: Checklist for Autism in Toddlers (CHAT)
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