title: Evaluating Reliability and Predictive Validity of the Persian Translation of Quantitative Checklist for Autism in Toddlers (Q-CHAT).
abstract: OBJECTIVE
  Early screening of autism increases the chance of receiving timely intervention. Using the Parent Report Questionnaires is effective in screening autism. The Q-CHAT is a new instrument that has shown several advantages than other screening tools. Because there is no adequate tool for the early screening of autistic traits in Iranian children, we aimed to investigate the adequacy of the Persian translation of Q-CHAT.
  
  
  METHODS
  At first, we prepared the Persian translation of the Quantitative Checklist for Autism in Toddlers (Q-CHAT). After that, an appropriate sample was selected and the check list was administered. Our sample included 100 children in two groups (typically developing and autistic children) who had been selected conveniently. Pearson's r was used to determine test-retest reliability, and Cronbach's alpha coefficient was used to explore the internal consistency of Q-CHAT. We used the receiver operating characteristics curve (ROC) to investigate whether Q-CHAT can adequately discriminate between typically developing and ASD children or not. Data analysis was carried out by SPSS 19.
  
  
  RESULTS
  The typically developing group consisted of 50 children with the mean age of 27.14 months, and the ASD group included50 children with the mean age of 29.62 months. The mean of the total score for the typically developing group was 22.4 (SD=6.26) on Q-CHAT and it was 50.94 (SD=12.35) for the ASD group, which was significantly different (p=0.00).The Cronbach's alpha coefficient of the checklist was 0.886, and test-retest reliability was calculated as 0.997 (p<0.01). The estimated area under the curve (AUC) was 0.971. It seems that the total score equal to 30 can be a good cut point to identify toddlers who are at risk of autism (sensitivity= 0.96 and specificity= 0.90).
  
  
  CONCLUSIONS
  The Persian translation of Q-CHAT has good reliability and predictive validity and can be used as a screening tool to detect 18 to 24 months old children who are at risk of autism.
authors.affiliation: Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Mohammadian
authors.affiliation: Tehran University of Medical Sciences, Psychiatry & Psychology Research Center, Tehran, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Zarafshan
authors.affiliation: Tehran University of Medical Sciences, Psychiatry & Psychology Research Center, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Mohammadi
authors.affiliation: Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Issa
authors.initials: I
authors.lastname: Karimi
keywords: Autism; Early Screening; Predictive Validity; Q-CHAT; Reliability