Predicting developmental outcomes in very preterm infants: validity of a neonatal neurobehavioral assessment

Abstract

This study explored inter-rater reliability, discriminative, construct and predictive validity of the Neurobehavioral Assessment of the Preterm Infant (NAPI) in a gestational-age-based cohort. The NAPI was conducted at 35 weeks post-menstrual age for 170 infants born <32 weeks. Cognitive and motor development was assessed at 2 years using the Mental Development Index (MDI) and Psychomotor Development Index (PDI) of Bayley Scales of Infant Development-II for 159 infants. Only NAPI motor and irritability scores were significantly different between very (29-3 w) and extremely preterm (<28 w) infants. Results regarding construct validity were variable: there were weak correlations between NAPI motor scores and gestational age (r = -0.23; p = 0.003), days in NICU (r = -0.24; p = 0.001); NAPI alertness scores and days in NICU (r = -0.16; p = 0.037); and NAPI irritability scores and gestational age (r = 0.21; p = 0.006). There were no significant associations with other markers of adverse outcome. Only NAPI irritability scores were correlated with MDI scores (r = -0.16; p = 0.040) but accounted for little additional variance after adjustment for neonatal factors (ΔR(2) = 0.035; p = 0.012). We found little evidence of the utility of the NAPI as a measure of short-term neurobehavioural function or for predicting neurodevelopmental outcomes in very preterm infants. It may have greater predictive power when used serially to detect delayed neurobehavioural maturation.