Table 2

Demographic characteristics

No missing data (N = 264789)

Any missing data (N = 82297)

Maternal Age: mean (std) *

28.3 (5.4)

26.8 (5.7)

Maternal Education: mean (std) *

13.3 (2.6)

11.8 (2.7)

Maternal Race: (N, %) *

White

219455 (82.9%)

46483 (64.3%)

Black

6078 (2.3%)

5647 (7.8%)

Asian & Pacific Islander

16072 (6.1%)

6378 (8.8%)

Hispanic

19271 (7.3%)

11081 (15.3%)

Native American & other

3913 (1.5%)

2742 (3.8%)

Paternal Age: mean (std) *

30.7 (6.1)

30.4 (6.7)

Paternal Education: mean (std) *

13.4 (2.7)

12.8 (3.9)

Paternal Race: (N, %) *

White

217539 (82.2%)

25572 (60.1%)

Black

9615 (3.6%)

3644 (8.6%)

Asian & Pacific Islander

13184 (5.0%)

4098 (9.6%)

Hispanic

20625 (7.8%)

8267 (19.4%)

Native American & other

3826 (1.4%)

944 (2.2%)

Married mother: (N, %) *

238092 (89.9%)

37213 (45.2%)

LBW at delivery: (N, %) *

9337 (3.5%)

5202 (6.3%)

Demographic characteristics and rate of low birthweight at delivery for births with and without missing data. N = number of births; std = standard deviation. LBW = low birthweight. * P < 0.001

Nicolaidis et al. BMC Pregnancy and Childbirth 2004 4:10   doi:10.1186/1471-2393-4-10