RESUMEN
OBJECTIVES: We aimed to assess the test-retest reliability, internal consistency, and validity of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT). METHODS: The Korean version of the Q-CHAT and the Korean version of the Child Behavior Checklist (CBCL) 1.5-5 were completed by parents of 24 toddlers and preschoolers with autism spectrum disorder (ASD) and 80 unselected toddlers and preschoolers. Parents of the ASD group also completed the Social Communication Questionnaire (SCQ), and Childhood Autism Rating Scale (CARS) scores were obtained from medical records. RESULTS: The ASD group scored higher on the Q-CHAT than the unselected group. The Cronbach's alpha coefficient of the Q-CHAT was 0.658, and test-retest reliability was calculated to be 0.836. The estimated area under the curve was 0.793. The total scores of the Q-CHAT in the ASD group demonstrated significant positive correlations with findings regarding pervasive development problems in the CBCL, SCQ, and CARS. A total score of 33.5 may be a useful cutoff point to use when identifying toddlers at risk of ASD. CONCLUSION: The Korean version of the Q-CHAT has good reliability and validity and can be used as a screening tool in order to identify toddlers and preschool children at risk of ASD.