Table 1.

Summary of definitions of neurodevelopmental impairments used in assessments at 3 years of age included in the NRNJ database

Domain	Criteria for NDI
Motor	Cerebral palsy with GMFCS level 2
Visual	Blindness with no functional vision in at least one eye
Hearing	Hearing amplification required
Cognitive	DQ score of KSPD test <70, or judged as delayed by a pediatrician if the KSPD test was not available

NRNJ, Neonatal Research Network of Japan; NDI, neurodevelopmental impairment; GMFCS, Gross Motor Function Classification System; DQ, developmental quotient; KSPD, Kyoto Scale of Psychological Development.