International Meeting for Autism Research: Early Detection of Autism Spectrum Disorder at 18 Months

Early Detection of Autism Spectrum Disorder at 18 Months

Friday, May 13, 2011: 4:57 PM
Elizabeth Ballroom GH (Manchester Grand Hyatt)
4:45 PM
Y. Kamio1, N. Inada2, E. Inokuchi3 and K. J. Tsuchiya4, (1)Department of Child and Adolescent Mental Health, National Center of Neurology and Psychiatry, National Institute of Mental Health, Tokyo, Japan, (2)National Center of Neurology and Psychiatry, Japan, National Institute of Mental Health, Tokyo , Japan, (3)Department of Child and Adolescent Mental Health, National Institute of Metal Health, Tokyo, Japan, (4)Hamamatsu University School of Medicine, Hamamatsu

Recently reported prevalence of autism spectrum disorders (ASD) is 1-2% in Japan (Kamio et al., 2010; Kawamura, Takahashi, & Ishii, 2008) and the U.K. (Baird et al., 2006; Baron-Cohen et al., 2009). The Japanese government has started to promote health-social policy of early detection and intervention for children with ASD and their families. In Japan, although the child health checkup system from infants to 3-year-olds has been well established nationwide and the visit rate is over 90%, the 18- and 36-month checkups focus on language/intellectual development but not social development. Because socio-communication abnormalities begin to manifest at 1 year of age in ASD, the checkup at 18 months appears to provide a good opportunity to detect early symptoms of ASD. We considered that the Modified Checklist for Toddlers with Autism (M-CHAT), a 23-item, parent-report questionnaire (Robins et al., 2001), may complement and enhance the existing checkup system, since the checklist was developed for children 16-30 months of age and is easy to administer without increasing the burden on both the families and check-up staff. For these reasons, we developed the Japanese version of the M-CHAT. After a preliminary study (Kamio & Inada, 2006), with the permission of the authors, we added illustrations (items 7, 9, 17, and 23: see to help caregivers to recognize negative symptoms.


To examine whether the early ASD screening procedure using the Japanese M-CHAT (J-MCHAT, Inada et al., 2010) is effective when it is added to 18-month checkup in Japan similarly as in the U.S.


2113 children (94.2% of the total population, males 50.7%) who visited the 18-month health check-up (97.5% were between 18-19 months of age) in a suburb of Fukuoka, Japan were screened using the J-MCHAT with a 2-stage procedure, a parent-administered 23 item questionnaire screen and the M-CHAT Follow-up Interview (FUI) by telephone. We lowered the threshold at the 1st screening due to the younger age such that a child screened positive if he/she failed 3/23 or 1/10 critical items. 312 children were screen-positive at the 1st stage, and 42 children stayed positive at the 2nd stage and were invited for a developmental evaluation at age 2. A subgroup of screen-positive children and screen-negative children under the community health surveillance system were invited to developmental/diagnostic evaluations at 2, 3, 4, 5, 6 years of age, and each case received evaluations more than twice. Probable ASD was considered when a child was evaluated at 2 and showed ASD symptoms, did not attend follow-up evaluation, but surveillance at kindergarten or elementary school entry indicated likely ASD.


Twenty-nine children of 39 children later diagnosed as ASD/probably ASD were screen-positive at the 1st and 20 children were positive at the 2nd screening. Psychometrics for J-MCHAT alone are sens=.74, spec=.91, PPV=.15, and NPV=.99. When the J-MCHAT + FUI is considered, sens=.56, spec=.99, PPV=.69, and NPV=.99.


With a few modifications of threshold criteria according to age, the M-CHAT screening can successfully differentiate children with ASD from the other children at 18 months.

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