Concurrent Validity of the ABAS-II Questionnaire with the Vineland II Interview for Adaptive Behavior in a Pediatric ASD Sample: High Correspondence Despite Systematically Lower Scores

We examined the correlation between interviewer-administered Vineland Adaptive Behavior Scale II (VABS-II) and the parent-rated Adaptive Behavior Assessment System II (ABAS-II) questionnaire in 352 participants (ages 1.5–20.8 years) with autism spectrum disorder (ASD) to determine if ABAS could be used as a screen to reduce the number of VABS interviews. Corresponding domain scores between the two measures were highly correlated but scores were significantly lower on the ABAS-II. Screening with ABAS-II significantly reduced the number of VABS-II interviews required with little cost to overall accuracy. The ABAS-II provides a cost- and time-saving alternative to the VABS-II to rule out functional impairment; however, scores are not strictly comparable between the two measures.