45: The Movement Assessment of Infants (MAI) and the Alberta Infant Motor Scale (AIMS) at Four Months: Do they Accurately Predict 18-Months Outcome of Extremely Preterm Infants?

Abstract

The MAI and AIMS have been widely used to assess infant neuromotor status. Their predictive validity with the first editions of the Bayley has been modest. To examine the predictive validity of the MAI and AIMS at four months corrected age (CA) in determining neurodevelopmental outcome at 18 months (CA) using the Bayley Scales of Infant and Toddler Development 3rd edition (BSITD-3). This retrospective cohort study included all surviving infants <29 weeks gestation born at or admitted at a tertiary care university center in 2009 to 2011 and followed until 18 months. All were assessed at four months with the MAI and AIMS by a physiotherapist and at 18 months with the BSITD-3 by a psychologist, blinded to previous test scores, and for cerebral palsy (CP) by a physician. Abnormal results were: MAI ≥14, AIMS ≤5th percentile, Bayley score ≤85 or CP. Severe outcome was: Bayley ≤70, severe CP, bilateral blindness, severe bilateral neurosensory hearing loss. Characteristics for the 133 children were: mean (± SD) gestational age 26.2±1.4 weeks, birth weight 891±202 g, 55% boys, 25% multiples, 91% prenatal steroids, 95% inborn, 94% appropriate weight for age, 65% cesarean section; and for the mothers: 30.7±5.0 years; 68% caucasian, 62% college or university education. Risk factors were: 38% bronchopulmonary dysplasia with home oxygen, 11% severe retinopathy, 7% severe cerebral anomaly, 35% sepsis, 20% patent ductus with intervention, 10% necrotizing enterocolitis. Infants with normal MAI (≤13), compared to those with abnormal MAI (≥14), had higher cognitive, language and motor Bayley scores (all Anovas <.005); less cognitive or language score ≤85 and less severe global impairments (all χ2 <0.05). Motor score ≤85 and CP were not different. Classification according to AIMS normal or abnormal, to both tests normal, one test out of two abnormal or both tests abnormal did not improve prediction. In predicting severe outcomes the MAI had: 95% sensitivity, 47% specificity, 98% negative predictive value and 23% positive predictive value. Preterms with MAI scores ≤13 at four months have better outcomes than those with higher scores. However, both the MAI and AIMS do not strongly predict neurodevelopment status at 18 months.