SCREENING FOR DEVELOPMENTAL DELAY IN THE SETTING OF AN AMBULATORY PEDIATRIC CLINIC

Objectives: The goal was to prospectively test a developmental screening protocol, which could be used to screen children with possible developmental delay. Specific objectives included: 1) the feasibility of using parent-report instruments in the setting of a pediatric clinic; 2) the accuracy of two available screening tests-the Ages and Stages Questionnaire (ASQ), and the Child Developmental Inventory (CDI); 3 whether the pediatrician's clinical judgment could be used as a potential modifier.

Methods: Subjects were recruited over an 11 month period from the patient population of a pediatric clinic incorporating seven pediatricians and providing comprehensive primary pediatric care. Subjects without prior developmental delay or concerns were contacted at the time of their routine 18-month old visit. Those subjects who agreed were randomized to one of two groups and completed either the ASQ or CDI. The pediatrician completed a brief questionnaire regarding his/her opinion of the child's development. Those children for whom concerns were identified by the screening instrument or the pediatrician underwent detailed testing by the Battelle Development Inventory (BDI), the gold standard for the purposed of this study. An equal number of children scoring within the norms of the screening measures also underwent BDI testing. Psychometric values were calculated from the data collected.

Results: Of the 397 parents whom we contacted, 354 parents (89%) agreed to participate. Most parents correctly completed the ASQ (82%) and the CDI (74%). The following psychometric variables were calculated for ASQ, the CDI and pediatrician's opinion respectively: for sensitivity 0.67, 0.50 and 0.46; for specificity 0.37, 0.86 and 0.87; for positive predictive value 0.37, 0.50 and 0.59 and finally for negative predictive value 0.70, 0.86, and 0.79. Incorporating the physician's opinion regarding the developmental status of the child did not improve the accuracy of the screening questionnaires.

Conclusion: These questionnaires can be feasibly used in the setting of a pediatric clinic. Since neither test had psychometric values indicating consistent accuracy, a single screening instrument at one point in time may not be sufficient to accurately estimate the developmental status of a child. This study does raise important questions about how developmental screening can be performed and suggests that screening should occur over time.