Developmental quotient to estimate intelligence in autism spectrum disorder

Background Autism spectrum disorders (ASD) are characterized by persistent deficits in social communication and social interaction across contexts, and are associated with restricted patterns of behavior. The developmental quotient (DQ) is based on the developmental age and chronological age of children. This study investigated the utility of the DQ to estimate cognitive ability in young children with ASD. Methods The DQ and intelligence quotient (IQ) were assessed using the Kyoto Scale of Psychological Development 2001 (KSPD) and Wechsler Intelligence Scale for Children‐III (WISC‐III), respectively. The correlation between the DQ and IQ was then analyzed among children with ASD. Results We enrolled 18 children with ASD (16 boys, two girls; age, 63.6 ± 9.4 months; age range, 45–83 months). Overall, Cognitive‐Adaptive and Language‐Social DQ scores were significantly correlated with IQ score in the full scale, verbal, and performance domains. Full‐scale IQ and overall DQ had a linear correlation (y = −22.747 + 1.177x, R2 = 0.677, R = 0.823). Conclusions The DQ scores obtained using the KSPD were a reasonable estimate of cognitive ability in children with ASD. The KSPD may be a useful alternative to the WISC‐III for young children with ASD and could facilitate earlier assessment.