Table 1.
Demographics
| Characteristic | n = 13,926 |
|---|---|
| Gestational age (weeks), No. (%) | |
| 23–24 | 3113 (22) |
| 25–26 | 6818 (49) |
| 27–28 | 3995 (29) |
| Birth weight (g), No. (%) | |
| 400–600 | 2019 (15) |
| 601–800 | 5978 (43) |
| 801–1000 | 5929 (42) |
| Small for gestational age, No. (%) | 2486 (18) |
| Race/ethnicity, No. (%) | |
| White | 5699 (42) |
| Black | 4328 (32) |
| Hispanic | 2622 (20) |
| Other | 782 (6) |
| Male, No. (%) | 6831 (49) |
| Postnatal age at first immunization (days), median (IQR) | 64 (60–72) |
| Weight at first immunization (g), median (IQR) | 1988 (1735–2235) |
| Number of immunizations received, No. (%) | |
| 1 | 559 (4) |
| 2 | 664 (5) |
| 3 | 9260 (66) |
| 4 | 1096 (8) |
| 5+ | 2347 (17) |
| History of sepsis prior to day 53, No. (%) | 2904 (21) |
Abbreviation: IQR, interquartile range.