Table 1: Demographic characteristics of study sample [mean ± standard deviation or (%)].

African-American ()White ()

Median income (US Dollars) $37,113 ± $14,690$44,081 ± $13,192
 Low (<$31,389)2986 (38.4%)1138 (13.1%)
 Middle ($31,389–$48,466)3287 (42.2%)4942 (56.9%)
 High (>$48,466)1508 (19.4%)2611 (30.0%)
Maternal age (years)17.87 ± 1.2618.08 ± 1.09
 Age <171145 (14.7%)852 (9.8%)
 Age 17–196636 (85.3%)7839 (90.2%)

All differences between racial categories were significant at < 0.001.