Background: Developmental screening tests, even those meeting standards for screening test accuracy, produce numerous false-positive results for 15% to 30% of children. This is thought to produce unnecessary referrals for diagnostic testing or special services and increase the cost of screening programs.

Objectives: To explore whether children who pass screening tests differ in important ways from those who do not and to determine whether children over-referred for testing benefit from the scrutiny of diagnostic testing and treatment planning.

Methods: Subjects were a national sample of 512 parents and their children (age range of the children, 7 months to 8 years) who participated in validation studies of various screening tests. Psychological examiners adhering to standardized directions obtained informed consent and administered at least 2 developmental screening measures (the Brigance Screens, the Battelle Developmental Inventory Screening Test, the Denver-II, and the Parents’ Evaluations of Developmental Status) and a concurrent battery of diagnostic measures, including tests of intelligence, language, and academic achievement (for children aged 21⁄2 years and older). The performance on diagnostic measures of children who failed screening but were not found to have a disability (false positives) was compared with that of children who passed screening and did not have a disability on diagnostic testing (true negatives).

Results: Children with false-positive scores performed significantly (p< .001) lower on diagnostic measures than did children with true - negative scores . The false-positive group had scores in adaptive behavior, language, intelligence, and academic achievement that were 9 to 14 points lower than the scores of those in the true-negative group. When viewing the likelihood of scoring below the 25th percentile on diagnostic measures, children with false-positive scores had a relative risk of 2.6 in adaptive behavior (95% confidence interval [CI], 1.67- 4.21), 3.1 in language skills (95% CI, 1.90-5.20), 6.7 on intelligence tests (95% CI, 3.28-13.50), and 4.9 on academic measures (95% CI, 2.61-9.28). Overall, 151 (70%) of children with false-positive results scored below the 25th percentile on 1 or more diagnostic measures (the point at which most children have difficulty benefiting from typical classroom instruction) in contrast with 64 (29%) of the children with true-negative scores (odds ratio, 5. 6; 95% CI , 3. 73- 8. 49) . Children with false-positive scores were also more likely to be nonwhite and to have parents who had not graduated from high school. Performance differences between children with true-negative scores and children with false-positive scores continued to be significant (p < .001) even after adjusting for sociodemographic differences between groups.

Conclusions: Children overreferred for diagnostic testing by developmental screens perform substantially lower than children with true-negative scores on measures of intelligence, language, and academic achievement—the 3 best predictors of school success. These children also carry more psychosocial risk factors, such as limited parental education and minority status. Thus, children with false-positive screening results are an at-risk group for whom diagnostic testing may not be an unnecessary expense but rather a beneficial and needed service that can help focus intervention efforts. Although such testing will not indicate a need for special education placement, it can be useful in identifying children’s needs for other programs known to improve language, cognitive, and academic skills, such as Head Start, Title I services, tutoring, private speech-language therapy, and quality day care.