TABLE 2

Demographic Factors of Participants and Nonparticipants at Current Sweep

CharacteristicsParticipantsNonparticipantsP
Number of participants
 Overall189135
 NBW8956
 ELBW10079
Male, n
 NBW3333.01
 ELBW3945.02
Birth weight, g (SD)
 NBW3388.1 (465.6)3348.5 (526.5).64
 ELBW834.9 (132.7)840.5 (110.0).76
Gestational age, mean (SD), wk
 NBW4040
 ELBW26.8 (2.0)27.1 (2.4).36
NSI
 NBW12.31
 ELBW2625.41
Small for gestational age
 NBW
 ELBW2914.08
Childhood SES
 NBW33.42
 ELBW34<.01
WISC-R full scale IQ
 NBW106.2 (11.7)100.1 (12.3)<.01
 ELBW93.4 (15.8)87.2 (15.4).03
WISC-R performance IQ
 NBW108.1 (12.5)103.0 (12.4).02
 ELBW94.9 (16.9)91.1 (16.6).21
WISC-R verbal IQ
 NBW103.6 (12.4)97.6 (13.1).01
 ELBW93.5 (15.0)85.8 (15.0).01
Woodcock–Johnson standard score
 NBW99.8 (13.9)95.9 (14.4).11
 ELBW91.6 (16.0)85.5 (14.6).03
WRAT-R arithmetic standard score
 NBW95.3 (13.6)92.5 (13.0).22
 ELBW83.4 (16.2)80.3 (17.9).31