Investigating the validity of the Ages and Stages Questionnaire to detect gross motor delays in a community sample of toddlers: A cross-sectional study

OBJECTIVE: Gross motor (GM) development delays often appear in the toddler years but may not be diagnosed until school age. Early identification and intervention can improve motor outcomes. The Peabody Developmental Motor Scales - 2nd edition (PDMS-2) can assess GM skills but is resource-intensive. A parent-reported questionnaire, the Ages & Stages Questionnaire - 3rd edition (ASQ-3), may be a simple and effective way to flag potential GM delays requiring follow-up. This study aims to investigate the concurrent validity of the ASQ-3 GM subscale and the PDMS-2 GM subscale in toddlers and determine if the ASQ-3 GM subscale can accurately identify toddlers with motor delays. STUDY DESIGN: 103 healthy toddlers (12-35 months) completed the PDMS-2 GM assessment and parents completed the ASQ-3. The relationship between ASQ-3 GM and PDMS-2 GM was assessed with Kendall's Tau-b correlation, and contingency tables assessed the sensitivity, specificity, and positive and negative predicted values. RESULTS: The Kendall's Tau-b correlation showed a moderate to strong correlation between the ASQ-3 GM raw scores and PDMS-2 GM quotient scores (tau-b = 0.51, p < 0.0001). The monitor zone cut-off on the ASQ-3 had a sensitivity of 67 % and specificity of 85 % for identifying children scoring >1SD on the PDMS-2. CONCLUSIONS: The moderate-to-strong correlation between the ASQ-3-GM and PDMS-2-GM, adequate specificity and near-adequate sensitivity of the ASQ-3 combined with low resource requirements suggests that the ASQ-3 can be employed at a population level to identify toddlers with a delay and who may require referrals for further GM testing and intervention.