Abstract

to analyse the reliability of 6 age intervals of Spanish web-based Ages and Stages Questionnaires Third Edition (WB-ASQ-3) and parents' acceptability, in a clinical practice context, during COVID-19 pandemic and lockdown in Chile. Cross-sectional study with a longitudinal component. Internal consistency was analysed by Cronbach's alpha and Pearson product-moment correlation, Pearson's correlations between intervals questionnaires were analysed. Acceptability was determined using a parental satisfaction survey. 1061 children completed 2318 validated questionnaires. Scores were compared with normative sample, except for Gross motor at 8 and 12 months, and Communication at 12, 18 and 24 months, without differences to the previous Chileans sample. In domain analysis, Cronbach's alpha ranged from 0.36 to 0.80 and reached 0.74 to 0.81 for the overall test. Strong positive correlation between the domain and overall score was obtained. Correlation between most questionnaires at different ages was positive and significant. Parental surveys show high satisfaction; parents were thankful for being able to monitor children's development. WB-ASQ-3 is a reliable and feasible screening system, particularly when the test is taken as a whole, rather than by domains. It is remarkably high acceptability among parents, especially in complex times such as the lockdown and the COVID-19 pandemic.