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 <2 SDs below the mean area score was considered a positive screen (indicating failure or delay). A Bayley-III score less than ≤1 SD indicated mild or severe delay. ASQ-3 showed adequate psychometric properties (75% sensitivity and 81% specificity) and modest agreement with the Bayley-III (r = 0.56). Sensitivity, specificity, and correlations between measures improved with testing age and in children who were born extremely preterm. Considering its psychometric properties, the ASQ-3 can be recommended for routine use in screening low-risk children at 8, 18, and 30 months' CGA and is advisable to be included in follow-up programs for children with biological risk factors such as those born preterm.