Accuracy of Parental Report of Infants' Motor Development

Previous research with developmentally delayed children has suggested that parents are able to give accurate estimates of their child's developmental levels (2, 3) . Parents' perception of their infants' developmental status has been successfully used in screening for sensorimotor and intellectual abnormalities ( 4 ) . While previous research with parents has employed general, wide-ranging questionnaires designed to assess language, personal-social growth, play, self-help, and gross and fine-motor skills, a search of the literature did not yield any study which compared parents' detailed report of motor development alone with performance on an objective measure of infants' motor ability. Given the evidence that infants' motor status may be more predictive of later neurological impairment and IQ than infants' mental status (1, 5 ) , it may prove clinically effective to question parents about their infants' motor development. The present study compared parental reports of motor development with obtained scores on the Motor Scale of the Bayley Scales of Infant Development for 72 (44 boys and 28 girls) infant graduates of an intensive care nursery (mean age 12.17 mo., SD .09 mo). Subjects were all infants seen consecutively between July 1984 and November 1984 in a longitudinal follow-up study at a university-based child study center. None of the children had received previous developmental testing. The mean Bayley Mental Development Index (corrected for gestational age) was 98.91 ( S D 25.5), suggesting that on average the infants' cognitive development was normal. Parents' perception of motor development was obtained by administration of the Motor Scale Survey Form of the Vineland Adaptive Behavior Scales (ABS) ( 6 ) ; scores on this instrument were then compared with infants' scores on the Bayley Motor Scale. The mean Bayley Motor Scale age equivalent was not significantly higher than the parents' reported Vineland ABS age equivalent (Ms 10.40 versus 10.34 mo., respectively; t = .03, p > .05). The Pearson correlation between Bayley and Vineland ABS scores was .86, indicating a strong relationship 'between arrays. Using the Bayley Motor scores as the criterion variable and a cut-off criterion score of -1 SD, 68 of the 72 infants (94.4%) were correctly classified as normal-abnormal on the Vioeland ABS Motor Scale. Of the four errors of classification, only one was a false negative, i.e., the sensitivity of the scale was 88.8%. The other three errors were false positives or "overreferral" type errors, yielding a specificity percentile of 95.2. It was apparent then, that parents of our sample of 1-yr.-old graduates of an intensive care nursery were able to give accurate accounts of their infants' motor age development. This finding supports the claim of the authors of the Vineland scales that the survey may be used as a d~agnostic evaluation tool.