What is the recommended approach for developmental screening and evaluation in a child, including timing, tools, and referral criteria?

Developmental Screening and Evaluation: Recommended Approach

All infants and children should undergo developmental surveillance at every well-child visit, with standardized developmental screening using validated tools at 9,18, and 30 (or 24) months of age, with immediate referral to early intervention services for any child with a positive screen or parental concern. 1, 2, 3

Timing of Screening

The evidence strongly supports a structured screening schedule:

• Universal screening at 9,18, and 30 months using standardized tools 2, 3
• Some guidelines recommend screening at 24 months instead of 30 months 2
• Additional screening at 4-5 years (prior to school entry) if any concerns arise 3
• Continuous developmental surveillance at every well-child visit regardless of screening schedule 1, 3

Special Populations Requiring Intensified Surveillance

• Siblings of children with autism spectrum disorder (ASD): Screen at minimum at 18 and 24 months, as recurrence risk is 14-18% compared to general population risk 4
• Infants with hearing loss risk factors: Diagnostic audiology assessment by 24-30 months, with earlier and more frequent assessment for those with CMV infection, progressive hearing loss syndromes, neurodegenerative disorders, trauma, postnatal infections, ECMO, or chemotherapy 1

Recommended Screening Tools

Parent-completed tools are preferable to directly administered tools in primary care due to time constraints and comparable accuracy 2, 5.

General Developmental Screening (Broadband Tools)

The most extensively validated parent-completed tools include:

• Ages and Stages Questionnaire (ASQ) - extensively evaluated with good psychometric properties 2, 5, 6
• Parents' Evaluation of Developmental Status (PEDS) - well-validated and widely used 4, 2

Both tools have sensitivity of 70-80% and specificity of approximately 80%, which are the accepted standards for developmental screening 2.

ASD-Specific Screening

For autism-specific concerns, screen at 18 and 24 months 4:

• M-CHAT (Modified Checklist for Autism in Toddlers): Most extensively studied ASD-specific tool with PPV of 0.54 for ASD and 0.98 for any developmental disorder in children 18-30 months 4
• Important caveat: Screening before 24 months has higher false-positive rates (PPV 0.28 at 16-23 months vs. 0.61 at 24-30 months), but still identifies children needing intervention 4

Level 2 Screening Tools

For children who screen positive or are at high risk:

• Screening Tool for Autism in Two-Year-Olds (STAT): Sensitivity 92%, specificity 85% in 2-year-olds referred for suspected ASD 4
• CSBS DP Infant/Toddler Checklist: Can detect autism by first birthday, though not ASD-specific; PPV 0.75 for detecting any developmental delay 4

Referral Criteria

Refer immediately for any of the following 3, 5:

• Positive screen on standardized developmental tool
• Parental concern about development at any visit
• Failure of speech-language portion of global screening 1
• Clinical concern identified during surveillance

Referral Pathways

Children under 3 years: Refer to early intervention (EI) services - federally mandated under Individuals with Disabilities Education Act 2, 3

Children 3 years and older: Refer to school-based programs, though private school children may lack access to these resources 7

Concurrent referrals for children with confirmed delays 1, 3:

• Genetics consultation for hearing loss or unexplained developmental disabilities
• Otolaryngology evaluation for hearing concerns
• Ophthalmology for visual assessment
• Speech-language pathology for communication delays
• Developmental and behavioral pediatrics for comprehensive evaluation

Implementation Strategy

Workflow Integration

The evidence identifies time constraints as the primary barrier (cited by 82% of clinicians) 2. To overcome this:

• Use parent-completed questionnaires that can be filled out in waiting room
• Integrate screening into existing well-child visit structure
• Establish clear referral pathways and central referral points 1
• Ensure bidirectional communication with early childhood programs 3

Common Pitfalls to Avoid

1. Relying on clinical judgment alone: Physician impression alone misses 45% of children eligible for early intervention 2
2. Delaying referral: Children with positive screens should be referred immediately, not monitored over time 3, 8
3. Missing high-risk populations: Siblings of children with ASD require intensified surveillance beyond standard screening 4
4. Inadequate follow-up: 42.5% of children with positive screens are not referred, creating disparities in care 8

Addressing Disparities

Recent evidence shows that standardized screening reduces racial disparities - White children are more likely to be referred before screening, while non-White children benefit from screening-triggered referrals 8. This underscores the importance of universal screening rather than selective approaches.

Diagnostic Evaluation

For children with developmental disabilities without explainable cause:

• Chromosomal microarray testing or exome sequencing is recommended 7
• Comprehensive developmental and medical evaluations should follow positive screens 3

Quality Metrics

Target outcomes to monitor:

• Percentage of children screened at recommended intervals
• Time from positive screen to completed referral (should be <90 days) 9
• Percentage of screen-positive children who complete diagnostic evaluation

The evidence demonstrates that early intervention is effective in high-risk children and associated with improvements in cognitive and academic performance 5, making timely identification and referral critical to optimizing long-term outcomes.