Objective: To determine the concurrent validity of the Ages & Stages Questionnaires, Third Edition, Thai-version (ASQ-3 Thai) with the Denver Developmental Screening Test II (DDST-II) and agreement between them in developmental status screening in toddlers.
Material and Method: Children at the ages of 18, 24, and 30 months were enrolled. Each age group included 15 normal and 15 suspected cases. Participants were developmentally assessed by the DDST-II performed by a developmental pediatrician (BS). Parents of the enrolled children simultaneously completed their toddler’s age-specific version of the ASQ-3 Thai questionnaire. Concurrent validity of the ASQ-3 Thai with DDST-II was determined by descriptive statistics using the cross tabulation technique. Kappa analysis was used to calculate agreement between the ASQ-3 Thai and DDST-II.
Results: A fair to moderate agreement (Kappa agreement = 0.338-0.606) was found between the ASQ-3 Thai and the DDSTII. Sensitivity of the ASQ-3 Thai with DDST-II at the age of 18, 24, and 30 months were 66.7%, 88.2%, and 54.5%, respectively. Specificity of the tool when compared to the DDST-II were 78.6%, 71.4% and 90.9%, respectively.
Conclusion: This was a preliminary study of the ASQ-3 Thai version for developmental screening in clinical setting. Due to a fair to moderate agreement but low sensitivity between the ASQ-3 Thai and DDST-II, other validated tools should accompany the clinical usage of the tool. Further investigations are needed to support its usage, particularly the validation of the tool with other standardized developmental diagnostic tools.

Keywords: ASQ-3 Thai, DDST-II, Developmental screening