Which Bayley-III cut-off values should be used in different developmental levels?

Area of Science:

• Developmental Pediatrics
• Child Psychology
• Neurodevelopmental Disorders

Background:

• The Bayley Scales of Infant and Toddler Development (Bayley-III) and its predecessor (BSID-II) are standard developmental assessment tools.
• Previous studies indicated higher Bayley-III scores compared to BSID-II, particularly in infants and premature infants.
• This study investigates the generalizability of these inflated Bayley-III scores across various pediatric disease groups and age ranges.

Purpose of the Study:

• To evaluate if Bayley-III scores are inflated across diverse pediatric populations (6–42 months) with different diseases.
• To determine appropriate Bayley-III cut-off points for identifying mild, moderate, and severe developmental delays, calibrated against BSID-II standards.
• To assess the risk of underestimating developmental delays using current Bayley-III scoring conventions.

Main Methods:

• Administered both Bayley-III and BSID-II assessments to 255 children aged 6–42 months with various conditions.
• Collected data between November 2017 and April 2018.
• Utilized Receiver Operating Characteristic (ROC) analysis to establish new cut-off scores.

Main Results:

• Bayley-III Cognitive Composite (CC) and Motor Composite (MC) scores were significantly higher than BSID-II Mental Development Index (MDI) and Psychomotor Developmental Index (PDI) scores, respectively (p < 0.001).
• Cognitive delay prevalence decreased from 49.4% (BSID-II) to 23.1% (Bayley-III CC), and motor delay from 69.3% (BSID-II PDI) to 34.3% (Bayley-III MC).
• ROC analysis yielded recommended Bayley-III cut-off scores: CLC (mild 92.5, moderate 83.2, severe 71.2) and MC (mild 98.5, moderate 86.5, severe 74.5).

Conclusions:

• Bayley-III scores require careful interpretation across all age groups and diagnoses due to potential inflation.
• There is a significant risk of underestimating developmental delays when using standard Bayley-III cut-offs.
• Implementing the derived, lower Bayley-III cut-off scores is crucial for accurate classification of developmental delay severity.