Validation of the Korean Childhood Autism Rating Scale-2

Background: We aimed to evaluate the psychometric properties of the Korean version of the Childhood Autism Rating Scale Second Edition (K-CARS2), which is composed of the Standard Version (K-CARS2-ST) and the High Functioning Version (K-CARS2-HF). Method: A total of 340 participants were included in this study. We assessed 145 participants (aged 2–36 years, 78.0% male) for K-CARS2-ST and 65 participants (aged 6–36 years, 81.5% male) for K-CARS2-HF, all participants were clinically diagnosed with autism spectrum disorder (ASD). We also assessed 130 participants as a control group (62 with a clinical diagnosis other than ASD and 68 without any clinical diagnosis). Results: The results demonstrated that the K-CARS2 showed a high degree of internal consistency, inter-rater reliability, and test-retest reliability. In terms of correlations between the instruments, the results showed significant positive correlations. Factor analysis revealed a four-factor structure for K-CARS2-ST and a three-factor structure for K-CARS2-HF. To determine the discriminant validity, a discriminant analysis for between-group comparisons was conducted with the ASD and the control groups. The sensitivity and specificity values were both 100 for K-CARS2-ST and 100 and 96.0 for K-CARS2-HF, respectively.