Table 4.
Demographic characteristics of subject population (mean ± SD)
| Total set (n = 183) | Training set (n = 130) | Validation set (n = 53) | p-value | |
| Gestational age (weeks) | 29.3 ± 2.0 | 29.3 ± 2.0 | 29.1 ± 2.0 | 0.471 |
| Birth weight (grams) | 1164 ± 172 | 1170 ± 168 | 1145 ± 182 | 0.391 |
| Time on ventilator (~Age in days) (median) | 2 | 2 | 2 | -- |
| Sex | ||||
| Male | 52.5% (96/183) | 52.3% (68/130) | 52.8% (28/53) | 0.953 |
| Race | ||||
| Caucasian | 60.1% (110/183) | 62.3% (81/130) | 54.7% (29/531) | 0.233 |
| African-American | 36.6% (67/183) | 33.1% (43/130) | 45.3% (24/53) | 0 |
| Hispanic | 2.7% (5/183) | 3.8% (5/130) | 0 | -- |
| Asian | 0.5% (1/183) | 0.8% (1/130) | 0 | -- |
| Outcome | ||||
| Extubation Failure | 19.1% (35/183 | 16.9% (22/130) | 24.5% (13/53) | 0.243 |
1Pooled t-test; 2t-test for unequal variances; 3Chi-square test