Table 1.
Comparison of key variables at study baseline between those selected into the study and those not selected from the Adolescent Study
| Variable | Selected (N = 600) | Not Selected (N = 1420) | ||||||
|---|---|---|---|---|---|---|---|---|
| |
N |
Mean |
Std |
N |
Mean |
Std |
p-value |
|
| Birth weight (g) |
600 |
3387.8 |
493.3 |
1420 |
3353.7 |
533.0 |
0.92 |
|
| Gestation (days; LMP to term) |
600 |
282.1 |
12.7 |
1404 |
279.1 |
16.3 |
<.001 |
|
| Number of Previous Live Births |
600 |
1.7 |
1.7 |
1420 |
1.9 |
1.8 |
0.09 |
|
| |
N |
% |
|
N |
% |
|
p-value |
|
| Male |
300 |
50.0 |
|
703 |
49.5 |
|
0.84 |
|
| Mother Education at Child’s Birth |
|
|
|
|
|
|
|
|
| < High School |
74 |
12.3 |
|
169 |
11.9 |
|
0.58 |
|
| High School Graduate |
202 |
33.7 |
|
477 |
33.6 |
|
|
|
| Some College/Trade School |
200 |
33.3 |
|
444 |
31.3 |
|
|
|
| College Graduate or Higher |
123 |
20.5 |
|
329 |
23.2 |
|
|
|
| Missing |
1 |
0.2 |
|
1 |
0.1 |
|
|
|
| Maternal Smoking During Pregnancy |
|
|
|
|
|
|
|
|
| Never Smoked |
315 |
52.5 |
|
662 |
46.6 |
|
0.16 |
|
| Smokes Now |
180 |
30.0 |
|
490 |
34.5 |
|
|
|
| Smoked Until Current Pregnancy |
40 |
6.7 |
|
119 |
8.4 |
|
|
|
| Former Smoker |
61 |
10.2 |
|
136 |
9.6 |
|
|
|
| Missing | 4 | 0.7 | 13 | 0.9 | ||||
Data are presented as number, (N), mean and standard deviation (std).