Screening for autistic spectrum disorder in children aged 14-15 months. II: Population screening with the early screening of autistic traits questionnaire (ESAT). Design and general findings

A two-stage protocol for screening for autistic spectrum disorders (ASD) was evaluated in a random population of 31,724 children aged 14-15 months. Children were first pre-screened by physicians at well-baby clinics using a 4-item screening instrument. Infants that screened positive were then evaluated during a 1.5-h home visit by a trained psychologist using a recently developed screening instrument, the 14-item Early Screening of Autistic Traits Questionnaire (ESAT). Children with 3 or more negative scores were considered to be at high-risk of developing ASD and were invited for further systematic psychiatric examination. Eighteen children with ASD were identified. The group of children with false positive results had related disorders, such as Language Disorder (N = 18) and Mental Retardation (N = 13).