ABSTRACT
OBJECTIVE: To compare the scores of the Bayley Scales of Infant Development second edition (BSID-II) and the third edition, Bayley-III, in children with suspected developmental delay and to determine the cutoff score for developmental delay in the Bayley-III. METHODS: Children younger than 42 months (n=62) with suspected developmental delay who visited our department between 2014 and 2015 were assessed with both the BSID-II and Bayley-III tests. RESULTS: The mean Bayley-III Cognitive Language Composite (CLC) score was 5.8 points higher than the mean BSID-II Mental Developmental Index (MDI) score, and the mean Bayley-III Motor Composite (MC) score was 7.9 points higher than the mean BSID-II Psychomotor Developmental Index (PDI) score. In receiver operating characteristic (ROC) analysis of a BSID-II MDI score < 70, Bayley-III CLC scores showed a cutoff of 78.0 (96.6% sensitivity and 93.9% specificity). In ROC analysis of a BSID-II PDI score < 70, the Bayley-III MC score showed a cutoff of 80. CONCLUSION: There was a strong correlation between the BSID-II and Bayley-III in children with suspected developmental delay. The Bayley-III identified fewer children with developmental delay. The recommended cutoff value for developmental delay increased from a BSID-II score of 70 to a Bayley-III CLC score of 78 and Bayley-III MC score of 80.