Neonatal neurobehavior: a tale of two scales contrasting the NICU Network Neurobehavioral Scale with the NeoNatal Neurobehavioral Scale.

backgroundWithin the field of neonatology and infant neurology, the NICU Network Neurobehavioral Scale (NNNS) is a well-respected and well-used standardized assessment tool. In 2020, the Brown University's Center for the Study of Children at Risk announced a revision of the NICU Network Neurobehavioral Scale to the NeoNatal Neurobehavioral Scale, Second Edition (NNNS-II). The objective of this study was to characterize differences in the NNNS and NNNS-II in terms of construct computation and scoring.

methodsWe compared individual items tested between the two versions of the assessment. To compare the two assessments, we adapted the original NNNS to derive summary scores that aligned with the NNNS-II scoring rubric. To adapt original scores to fit the NNNS-II, a priori changes for the original NNNS scoring were determined to maintain consistency of observed behavior or response, and applied to real-world data.

resultsDespite a decrease in individual items assessed, the retained summary scores between the two scales demonstrate very strong association.

conclusionWe suggest the NNNS and NNNS-II perform similarly to characterize newborn neurobehavior. Though individual items may require recoding between assessments to retain fidelity of observation, revised summary scores also reflect related but unique constellations of these individual items. IMPACT: This study provides evidence of very strong agreement between NICU Network Neurobehavioral Scale (NNNS) and NeoNatal Neurobehavioral Scale, Second Edition (NNNS-II). Prior literature has not established the degree of agreement between these two versions of the assessment. Our findings provide strong evidence supporting their comparability. These findings suggest harmonization of data across studies using both the NNNS and NNNS-II to reduce barrier to longitudinal neonatal research.