Definition/Introduction
Bayley Scales of Infant and Toddler Development is an extensive formal developmental assessment tool for diagnosing developmental delays in early childhood. BSID is the commonly used abbreviation for Bayley Scales of Infant and Toddler Development. BSID scores are from a norm-referenced assessment of early childhood development. Nancy Bayley published the first BSID in 1969. The current BSID in use is BSID 4, published in 2019. BSID 4 is time-saving and has greater clinical sensitivity and accuracy when compared to BSD 3. It takes about 30 to 70 minutes to complete the test.
Infant and Childhood Development
Infant and childhood development comprises physical, cognitive, social-emotional, linguistic, and behavioral milestones. The differences in cultural, environmental, and genetic factors influence development. The development process is rapid and cumulative. Developmental disabilities are common and are reported in 1 in 6 children in the United States. The number of children with select developmental disabilities (autism, attention deficit hyperactivity disorder, and other developmental delays) has increased, requiring more health and education services.[1]
Developmental Assessments
An estimated 5 to 10% of the pediatric population has a developmental disability.[2] There are 3 different strategies to detect developmental delay.
Routine developmental surveillance is where the health care professional takes a short history and briefly examines it to elicit any developmental delay. Identification of developmental delay is ineffective when based solely on routine surveillance.
[2]A developmental screening tool is a systematic and structured tool to identify developmental delay. Although screening tools are cost and time-efficient, they are not diagnostic and have less utility in high-risk populations.
[3]Formal developmental tests are widely accepted and have a diagnostic utility.
Formal Developmental Assessment Tools
The purpose of the assessment and the age groups decide the type of tool used for formal development assessment. The evaluation varies depending on the clinician's skill and the family's needs and concerns. Some are norm-referenced, and some are criterion-referenced.
Following is the list of developmental assessment tools commonly used in practice.
Norm-referenced
BSID-4 - Bayley Scales of Infant Development-4
Battelle Developmental Inventory 3rd edition
DAYC-2: Developmental Assessment of Young Children-2
Criterion-referenced
AEPS - Assessment Evaluation & Programming System
ELAP - Early Learning Accomplishment Profile
IDA-2: Infant Toddler Developmental Assessment -2
Brigance Inventory of Early Development III (both)
The Bayley Scales of Infant and Toddler Development
The Bayley Scales has been in practice for several decades as a useful tool for detecting early developmental delay in clinical and research settings.[5] In 1969, Nancy Bayley published the first BSID. The first BSID assessed motor and mental domains in the age group from 3 to 28 months. BSID 2nd edition, published in 1993, added a behavior rating scale and widened the age group from 1 to 42 months. BSID-III, published in 2006, assessed development from 1 to 42 months in 5 domains - cognition, motor, language, socio-emotional, and adaptive behavior. BSID 4 was published in 2019 and is currently in use. BSID 4 retained the 5 domains from BSID III.
Difference between BSID III versus BSID 4
Scoring is Dichotomous (1, 0) in BSID III, whereas scoring is polytomous (2,1,0) in BSID4.
Compared to BSID III, BSID 4 takes approximately 30% less time to complete the assessment.
BSID 4 has questions for the caregiver.
Scoring is software-based in BSID III. BSID 4 scores need web-based administration.
BSID 4 retains the same 5 domains as BSIDIII. However, the number of items in each section has decreased.
BSID III has the following number of items in each domain
Cognitive scale - 91 items
Language scale - 49 items in the receptive and 48 items in the expressive domain
Motor scale - 66 items in the fine motor and 72 items in the gross motor domain
Social-Emotional Scale derived from Greenspan Chart.
Adaptive behavior scale derived from ABAS (Adaptive behavior assessment system)
BSID4 has the following number of items
Cognitive scale - 81 items
Language scale - 42 items in the receptive and 37 items in the expressive domain
Motor scale - 46 items in the fine motor and 58 items in the gross motor domain
Social-Emotional Scale is unmodified from Bayley III.
The adaptive behavior scale utilizes the Vineland behavior assessment system.
Purpose
The BSID determines children's developmental functioning and plans management for kids with developmental delays. BSID helps in the following ways.
Early identification of intellectual delay. Re-assessments can help to monitor progress over time.
To individualize the management and to accommodate a child's developmental and learning needs.
To assess individual domains of development, such as cognitive delay,
To help researchers as a research tool.
Pediatric professionals are critical in diagnosing developmental disabilities early.[6] BSID helps to detect developmental delay early and also to initiate early developmental intervention.
Target Age Group
BSID III and BSID -4 are used for the age group starting from 16 days to 42 months.
BSID Kit
Each BSID kit has a manual, forms, a booklet for the motor response, Social-Emotional, Adaptive Behavior domain questionnaires, caregiver reports, an observation Checklist, and a manipulative set. Cognitive, Language, and Motor scores assessment needs a web-based device. The questionnaire for caregivers includes socio-emotional and adaptive domains. Scores are given as polytomous, ranging from 0 to 2. In BSID-4 scoring, 2 are Mastery, 1 is emerging, and 0 means absent. After the assessment, the assessor summarizes standard and scaled scores. BSID administration requires training, which happens through webinars and workshops.
Preparation
The examiner explains to the caretaker what happens during the assessment. This helps establish rapport with the child and avoid parental concerns during the evaluation. The caretaker is advised not to talk or aid the child during the assessment, thereby avoiding skewed deviation.
Issues of Concern
Limitations and Precautions
BSID scores represent mostly the U.S. population. Testing conditions such as environmental, psychological, and physical impact BSID assessment scores profoundly. The development process is rapid, so a single assessment score gives only a snapshot of the current functioning level. BSID assessment is time-consuming and requires appropriate training. Knowing strengths and limitations helps in making diagnostic interpretations.
Prematurity and BSID
Preterm infants (born before 37 weeks gestation) are at risk for developmental delay.[7] Bayley scale can be used for preterm kids. However, age adjustment is made up to 2 years while administering BSID for preterm kids. Compared to previous editions of the BSID, the Bayley-III has excellent predictive validity for IQ assessment by WPPSI-III at age 4 years in preterm children.[8]
Risks
There are no risks associated with administering BSID.
Clinical Significance
Developmental disabilities are common and are reported in 1 in 6 children in the United States. Bayley Scales of Infant and Toddler Development is the most frequently used test in infant developmental assessment.[9] The Bayley Scales help detect developmental delays early and initiate early developmental intervention. BSID III and BSID 4 are used for the age group starting from 16 days to 42 months. The cognitive and language scales of the Bayley are a handy instrument for early diagnosis of Language disability.[10]
Nursing, Allied Health, and Interprofessional Team Interventions
Psychologists, neuropsychologists, or developmental pediatricians commonly administer the Bayley scale. Occupational therapists, speech and language pathologists, and pediatric nurse practitioners can also utilize Bayley III and Bayley 4. After appropriate training, anyone with proper qualifications can master Bayley. Bayley scales have excellent applicability for transdisciplinary or interdisciplinary teams as they can effectively identify children who need early intervention.[11]
