Description of Populations at Intervention and Control Centers
| Characteristic | Intervention Centers (N = 1752) | Control Centers (N = 2341) | ||
|---|---|---|---|---|
| Year 1 (N = 625) | Year 3 (N = 595) | Year 1 (N = 787) | Year 3 (N = 864) | |
| Birth weight, mean ± SD, g | 932 ± 207 | 922 ± 206 | 899 ± 209 | 912 ± 212 |
| PMA, mean ± SD, wk | 27.3 ± 2.3 | 27.3 ± 2.5 | 27.0 ± 2.3 | 27.1 ± 2.5 |
| PMA of <26 wk, n (%) | 151 (24.2) | 157 (26.4) | 229 (28.8) | 244 (28.2) |
| Male gender, n (%) | 338 (54.1) | 311 (52.3) | 394 (49.9) | 432 (50.2) |
| Race, n (%) | ||||
| White | 196 (31.4)a | 170 (28.6)a | 329 (41.8) | 365 (42.3) |
| Black | 191 (30.6) | 216 (36.3) | 368 (46.8) | 377 (43.6) |
| Other | 238 (38.1) | 209 (35.1) | 90 (11.4) | 122 (14.2) |
| Maternal age, mean ± SD, y | 27.2 ± 6.4 | 27.3 ± 6.7 | 27.2 ± 6.4 | 27.0 ± 6.3 |
| Prenatal steroid exposure, n (%) | 482 (77.1) | 470 (79.1) | 680 (86.4) | 761 (88.2) |
| Score of Neonatal Acute Physiology II, mean ± SD | 23.4 ± 15.0 | 24.6 ± 16.8 | 22.4 ± 14.6 | 19.5 ± 15.7 |
Comparisons of population characteristics in each group between study year 1 and study 3 were not significantly different, except for race in the intervention centers.
↵a P = .047.