Objectives: This study investigated the sensitivity and specificity of two brief, parent-completed developmental screening measures—the Ages and Stages Questionnaire (ASQ) and the Parents’ Evaluation of Developmental Status (PEDS®)—in children presenting to their primary care providers.
Method: A sample of 334 children aged 12 to 60 months was recruited. Parents completed the PEDS® and the ASQ in their home or the primary care clinic of one of the investigators. The presence of >1 predictive concerns or abnormal domains was considered a positive screen. All children underwent evaluation (administered by a psychologist) with the following criterion measures: the Bayley Scales of Infant Development—Third Edition or the Wechsler Pre- school and Primary Scale of Intelligence—Third Edition, the Preschool Language Scale—Fourth Edition, and the Vineland Adaptive Behavior Scales—Second Edition.
Results: The mean age of children was 32.3 months. Developmental delay was identified in 34 children (10%). The PEDS® had moderate sensitivity (74%) but low specificity (64%); comparatively, the ASQ had significantly higher sensitivity (82%) and specificity (78%). The ASQ had moderate sensitivity and specificity across age subgroups, whereas the PEDS® had either low sensi- tivity or specificity in each of the age subgroups, except for the <30 month group, where there was moderate sensitivity (78%) and specificity (75%). Using >2 predictive concerns on the PEDS® or >2 abnormal domains on the ASQ significantly improved specificity of both tests (89% and 94%, respectively) but resulted in very low sensitivity (41% and 47%, respectively).
Conclusions: These findings support the guidelines of the American Academy of Pediatrics, demonstrating that both the ASQ and, to a lesser extent, the PEDS® have reasonable test characteristics for developmental screening in primary care settings. Although the ASQ seems to have higher sensitivity and specificity across a variety of age groups, the choice of which measure to use should be determined by the practice setting, population served, and preference of the physician.
Comment from Dr. Glascoe: In response to the above paper, several researchers including the author of PEDS® and the ASQ, raised concerns about the overly strict definition of developmental delay. PEDS® is designed to identify children with milder delays, i.e., not just high risk but also at risk and this explains its lower specificity in comparison with the ASQ. In addition, it is not clear that the researchers dealt appropriately with PEDS® Response Forms on which nothing was written–these should either be met with a readministration by interview or discarded from studies. The in-press letter to the editor is below.
Glascoe FP, Marks KP, Squires J. Improving the Definition of Developmental Delay. JDBP. 2011, in press
To the Editor:
We compliment Drs. Limbos and Joyce on their careful and well-written study (Comparison of the ASQ and PEDS® in Screening for Developmental Delay in Children Presenting for Primary Care. The authors’ research was exemplary in viewing how well the ASQ and PEDS® performed in the identification of children with probable disabilities, i.e., those scoring below the 10th percentile and ostensibly eligible for early intervention/special education.
But the term ‘developmental delay’ also embraces those likely to fail in school—those performing above the 9thth percentile and below the 25th percentile. Such at-risk children rarely qualify for Early Intervention or special education but that does not mean they don’t need to be identified by screens as in need of other kinds of intervention (e.g., Head Start, Reach Out and Read, parent training, etc.).
Screens should identify not only disabled but also at-risk children and provide clinicians appropriate guidance for selecting diverse resources needed to help both groups. We encourage the authors to review their findings in order to speak to the complete meaning of developmental delay. Such an analysis seems likely to render different levels of sensitivity and specificity for both PEDS® and the ASQ.
Frances Page Glascoe, Ph.D.
Professor of Pediatrics
Kevin P. Marks, M.D., FAAP
PeaceHealth Medical Group
Eugene, Oregon 97401
Jane Squires, Ph.D.
Professor, College of Education
Director, Center on Human Development
Director, Early Intervention Program
University of Oregon