The Validity of Modified Checklist for Autism in Toddlers (M-CHAT) in Turkish

Background: The Modified Checklist for Autism in Toddlers (M-CHAT) is one of the specific measures designed for use in pediatric setting to identify toddlers at risk for autism (Robins et al, 2001). The psychometric properties of this instrument have been examined in several language and cultures however, there is no study investigating the psychometric properties of the M-CHAT in Turkish. 

Objectives:  To evaluate the validity of the M-CHAT (Modified Checklist for Autism in Toddlers) in Turkish, as a screening test for pervasive developmental disorders in children, in an 18-36 month-old sample from Istanbul. 

Methods:  : The M-CHAT questionnaire was filled out independently by 191 mothers and/or fathers, when they were waiting for the well-child examination of their child. A high screen positive rate was found. A telephone interview was carried out with parents to confirm the answers. At the telephone interview most positive screens reverted to negative. Because of this unacceptably high false positive rate, a second study was done, in which the M-CHAT was administered by healthcare staff in a short interview with parents to two groups. In the first group (high risk group), there were 80 children at 18-36 months of age, who were initially diagnosed with a Pervasive Developmental Disorder at the Child Neurology Department of Istanbul Medical Faculty, Istanbul University. In the second (low risk group), there were 538 children of the same age, who were regularly followed by the Well Child Clinic of Istanbul Medical Faculty, Istanbul University. Two screen positives were found in the low risk group. These two children, a random sample of the 120 children from the low risk group and all of the high risk group were invited to a clinical evaluation. Diagnostic evaluation was done using Childhood Autism Rating Scale (CARS) and DSM-IV-TR diagnostic criteria. The validity of the M-CHAT was assessed against clinical diagnosis and CARS.

Results:  The sensitivity, specificity, positive predictive value and negative predictive value of the M-CHAT test were found 95,7%, 88,7%, 75%, and 98,3%, respectively. 

Conclusions:  The validity of the M-CHAT in Turkey depends on the administration method. The sensitivity, specificity, positive and negative predictive value of M-CHAT were high, when the healthcare staff interviewed parents to complete the questionnaire. Our findings led us to conclude that M-CHAT is a useful tool in Turkey for screening of pervasive developmental disorders in primary care, after the age of 18 months, but that parents cannot complete it independently with specifity for autism.