Concurrent and predictive validity of the Motor Functional Development Scale for Young Children in preterm infants

Background: The Motor Functional Development Scale for Young Children (DF-mot) is a developmental tool assessing both gross and fine motor skills in term infants. Aims: To examine the concurrent validity of the DF-mot with the Alberta Infants Motor Scale (AIMS) in preterm infants and compare their ability in predicting scores on the Bayley Scales of Infant-Toddler Development (Bayley-III) at 12 months. Study design: Retrospective cohort study. Subjects and outcome measures: Hundred and eleven infants born at less than 32 weeks' gestation or with a birthweight less than 1500 g were assessed simultaneously on the DF-mot and the AIMS at age 3-5 months. Correlation analysis was used to determine the strength of association between the DF-mot and the AIMS. Among these, 62 were reassessed on the Bayley-III at age 9-12 months. Clinimetric properties were calculated to evaluate their ability to predict motor delay on the Bayley-III. Results: The concurrent validity study found a good level of correlation between the two scales (r = 0.79). The predictive validity study showed good sensitivity and negative predictive value for the AIMS 25th centile and the DF-mot-1 standard deviation to predict motor delay at 12 months (respectively Se = 100% and 84%; NPV = 100% and 77.8%). Conclusions: The DF-mot is a valid instrument with good predictive validity in preterm infants, suggesting it can be used as a clinical useful tool to assess motor development.