Reliability, validity and cut-off value of the childhood autism spectrum test

Abstract

Objective To explore the applicability of the childhood autism spectrum test (CAST) of children in Mainland China according to autism screening, in order to provide the effective reference for the identification and diagnosis of autism spectrum disorders of children. Methods Two hundreds and fifty-two typical developing children, and 61 autistic children who were confirmed by psychological clinic of Child Healthcare Clinic, Shenzhen Luohu District Maternal and Child Health Care Hospital who were conformed with diagnosis standards of Diagnostic and Statistical Manual of Mental Disorders Fifth Edition(DSM-5) by using CAST Chinese version were assessed, and the reliability and validity analysis were made on the CAST scale.The receiver operating characteristic curve was drew to determine the optimal threshold value, and the sensitivity, specificity and positive predictive value were calculated. Results CAST Chinese version had good reliability, Cronbach's α was 0.880.Split-half reliability coefficient r was 0.821, and the whole scale calibration reliability coefficient was 0.902.There was statistically significant difference between items and the total score(P< 0.05). The consistency between the CAST ≥4 years old children and diagnosis standards of DSM-5 reached 0.884(P=0.000). The consistency 3-<4 years old children and diagnosis standards of DSM-5 reached 0.867(P=0.000). Among the screening of the children who were ≥4 years old, the cut off was 15 scores that the sensitivity and specificity were best.With the children of 3-<4 years old, a designated cut-point should be 17 scores. Conclusions There are good reliability and validity of CAST, which can be used to mainland China, as well as to screen autistic children more than 3 years old. Key words: Autism spectrum disorder; Childhood autism spectrum test; Screen