Validity of the ages and stages questionnaires in term and preterm infants

This study assessed the concurrent validity of the parent-completed developmental screening measure Ages and Stages Questionnaires, Third Edition (ASQ-3) compared with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) in children born term, late preterm, or extremely preterm at 8, 18, or 30 months of corrected gestational ages (CGA). Data were collected from 306 term and preterm children ages 8, 18, and 30 months' CGA recruited from an ambulatory well-child clinic in Santiago, Chile. Parents completed the ASQ-3 in their homes, and afterward a trained professional administered the Bayley-III in a clinic setting. On the ASQ-3, the presence of any domain screened