Are overreferrals on developmental screening tests really a problem?

Background: Developmental screening tests, even those meeting standards for screening test accuracy, produce numerous false-positive results for 15% t o 30% of children. This is thought to produce unnecessary referrals for dia gnostic testing or special services and increase the cost of screening prog rams. 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 tr eatment 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 valida tion studies of various screening tests. Psychological examiners adhering t o standardized directions obtained informed consent and administered at lea st 2 developmental screening measures (the Brigance Screens, the Battelle D evelopmental Inventory Screening Test, the Denver-II, and the Parents' Eval uations of Developmental Status) and a concurrent battery of diagnostic mea sures, including tests of intelligence, language, and academic achievement (for children aged 2 1/2 years and older). The performance on diagnostic me asures of children who failed screening but were not found to have a disabi lity (false positives) was compared with that of children who passed screen ing and did not have a disability on diagnostic testing (true negatives). Results: Children with false-positive scores performed significantly (P<.00 1) lower on diagnostic measures than did children with true-negative scores . The false-positive group had scores in adaptive behavior, language, intel ligence, and academic achievement that were 9 to 14 points lower than the s cores of those in the true-negative group. When viewing the likelihood of s coring below the 25th percentile on diagnostic measures, children with fals e-positive scores had a relative risk of 2.6 in adaptive behavior (95% conf idence 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 meas ures (95% CI, 2.61-9.28). Overall, 151 (70%) of the children with false-pos itive results scored below the 25th percentile on 1 or more diagnostic meas ures (the point at which most children have difficulty benefiting from typi cal classroom instruction) in contrast with 64 (29%) of the children with t rue-negative scores (odds ratio, 5.6; 95% CT, 3.73-8.49). Children with fal se-positive scores were also more likely to be nonwhite and to have parents who had not graduated from high school. Performance differences between ch ildren with true-negative scores and children with false-positive scores co ntinued to be significant (P<.001) even after adjusting for sociodemographi c 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 wh om diagnostic testing may not be an unnecessary expense but rather a benefi cial and needed service that can help focus intervention efforts. Although such testing will not indicate a need for special education placement, it c an be useful in identifying children's needs for other programs known to im prove language, cognitive, and academic skills, such as Head Start, Title I services, tutoring, private speech-language therapy, and quality day care.