Ignoring screening results . Many times, screening test results are not taken seriously and children who fail are not referred but rather viewed with a wait and see attitude. Good screens are right 70 to 80 per cent of the time. Relying on informal methods . These are often based on instruments such as the original Denver Developmental Screening Test, which missed up to 50 per cent of mental retardation and 70 per cent of language impairment.
Checklists provide no validated criteria for referrals, and have unknown reliability.
Validated and standardized tools carry the burden of proof that informal measures lack. We would never select tools for blood lead or other medical screens with questionable or unknown levels of accuracy. Summary Developmental and Behavioral screening is a well-developed technology. These instruments are superior to informal methods that are now being used in many offices. Many instruments are also available in Spanish, and some in other languages.