Practice recommendations
- Do not rely on clinical judgment only or developmental milestone review for the timely identification of developmental delays (B).
- Screen children for developmental delays regularly with cost- and time-effective screens such as the Ages and Stages Questionnaire and PEDS (Parents’ Evaluation of Developmental Status) (C).
- Refer children with suspected delays promptly for comprehensive developmental assessment (C).
- Children with documented delays should receive prompt referral for appropriate early intervention (C).
One child out of 6 in your practice probably has a developmental disability.1 However, identifying disability will be erratic if you rely solely on clinical judgment and informal milestone reviews.
There is reason for concern: the evidence for early intervention, though limited, shows that it confers long-term benefits for these children. Judicious use of practical, reliable standardized screens that I discuss in this article will increase your likelihood of identifying children who need help.
Needed: A screening net with tighter mesh
Disorders such as cerebral palsy and profound mental retardation are clearly recognizable and have well-known consequences. Disabilities such as language impairment, mild mental retardation, and learning disabilities (see Range of disabilities) are more subtle but also associated with poorer health status, higher rates of school failure, in-grade retention, and special education placement.1,2
Developmental problems commonly escape detection in the first 5 years of life despite frequent well-child visits. Physicians generally acknowledge that screening for developmental disabilities is important,3 but few use standardized screening instruments.4,5 Most physicians rely instead on clinical judgment and milestone review.
Scope of the problem
A study that examined how doctors in the US screen for delays found that only 15% to 20% screened more than 10% of all of their patients with a formalized developmental instrument.5 Again, this points to reliance on clinical judgment to determine who should be screened. A National Survey of pediatricians and family physicians6 found that 53% reported using no standardized instrument in their assessment of children for developmental delays. The most recent National Survey of Early Childhood Health (NSECH)12 found that only 35% to 45% of parents recall their child’s development ever being assessed by their doctor.
Range of disabilities
Speech and language impairment are common among children (approximate prevalence 6%),7 as are learning disabilities (8%)8 and attention deficit disorder (7%).8 Less common conditions include mental retardation (1%–2%),9 cerebral palsy (0.2%),9 autism and autism spectrum disorders (0.5%).10 According to the US Department of Education, 13.2% of school-age children are in special education, most of them diagnosed with learning disabilities or mental retardation.11
The fallout. Most children who would qualify for early intervention under federal law are not identified before school entry. Palfrey et al13 examined the records of 1726 children in special education classes at 5 sites and found that just 28.7% of developmental and behavioral problems were identified before entry into school (age 5). Just 15% to 25% of learning and speech disorders emotional disorders and attention deficit disorders were identified before school entry.13
A study in the UK14 found that despite of a system geared to detect subtle developmental disorders, their child health surveillance failed to detect 38% of children with moderate learning disabilities and 94% of children with mild or moderate learning disabilities. Another study15 on this matter shows a disappointing detection rate, failing to identify 55% to 65% of children with developmental problems before entry into school.
Studies have proven clinical judgment insensitive even in the detection of mental retardation. Two studies from the 1960s showed that US pediatricians accurately identified only 43% of children with an intelligence quotient (IQ) of <80.
Does early intervention work?
Much of the literature on early intervention in childhood focuses on children with risk factors such as prematurity and low birth weight or low socioeconomic status. In controlled studies, children at psychosocial disadvantage who received high-quality intervention exhibited long-term improvement in IQ, higher academic achievement, and decreased criminal behavior, and were, as adults, more likely to be employed and to earn higher incomes than those who did not participate in early intervention (SOR: A).16,17
Other studies have similarly shown benefits from early intervention for children with such biological risk factors as low birth weight and prematurity (SOR: A).18 Early intervention for conditions such as learning disabilities or speech and language delays is generally thought to improve outcomes (SOR: C).2
Rationale for screening
Early identification mandated by law
The Individuals with Disabilities Education Act (IDEA) Amendments of 199719 mandate the “early identification of, and intervention for developmental disabilities through the development of community-based systems.” This law requires physicians to refer children with suspected developmental delays to appropriate early intervention services in a timely manner. All states receive federal funding to provide appropriate intervention through infant and child-find programs for children with developmental delays.