Validity of the Miller assessment for preschoolers in predicting later cognitive performance in children prenatally exposed to drugs

• Main Author: Fulks, Mary-Ann Lesley
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/4247

This study investigated the validity of the Miller Assessment for Preschoolers (MAP) in predicting later cognitive outcome in children with prenatal drug exposure, using the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R), the Test of Early Reading Ability (TERA-2), the Peabody Picture Vocabulary Test-Revised (PPVT-R), and the Developmental Test of Visual-Motor Integration (VMI) as the outcome measures. Criticisms of previous studies of the predictive validity of the MAP included the predominant use of correlational and t-test analysis rather than clinical epidemiological techniques, and the questionability of the predictive accuracy of the MAP's recommended 5th and 25th percentile cutpoints without investigation of the full possible range of cutpoints. The primary purpose of this study was, therefore, to investigate the predictive validity of the MAP over a range of cutpoints, using clinical epidemiological techniques. The secondary purpose of the study was to compare the subjects' test performance to each test's norms to investigate how this sample of children with prenatal drug exposure performed in comparison to each test's normative sample. The subjects were 37 children with prenatal drug exposure who were 35 - 49 months old at the time of administration of the predictor measure, and 47 - 68 months old at the time of administration of the outcome measures. The MAP demonstrated the highest level of predictive accuracy when the WPPSI-R was used as the outcome measure, suggesting it was the most successful in identifying later intelligence in this sample of children with prenatal drug exposure. It was less successful at predicting later outcomes for more specific cognitive areas such as early reading behavior, receptive vocabulary and visual-motor integration, as assessed by the other three outcome measures. The 14th percentile MAP cutpoint was found to demonstrate higher overall levels of predictive accuracy than the test's recommended 5th and 25th percentile cutpoints. Compared to each test's norms, this sample of children approximated the normal distribution on the WPPSI-R and PPVT-R, but performed closer to the low average range on the MAP, TERA-2 and VMI.