TABLE 1.
Demographics and Clinical Characteristics of the Study Infants
| Characteristica | All Infants N = 7549 | Low-Risk N = 1121 | Non-Low-Risk N = 6428 | P |
|---|---|---|---|---|
| GA (completed weeks), median, IQR | 37 (33–39) | 34 (30–37) | 38 (34–40) | <.001 |
| GA category (completed weeks), n, % | <.001 | |||
| <28 | 462 (6.1) | 113 (10.1) | 349 (5.4) | |
| 28–30 | 540 (7.2) | 170 (15.1) | 370 (5.8) | |
| 31–33 | 938 (12.4) | 232 (20.7) | 706 (11.0) | |
| 34–36 | 1480 (19.6) | 299 (26.7) | 1181 (18.4) | |
| ≥37 | 4123 (54.6) | 307 (27.3) | 3816 (59.4) | |
| BW (g), median, IQR | 2859 (2000–3440) | 2067 (1310–2910) | 2970 (2160–3490) | <.001 |
| BW category (g), n, % | <.001 | |||
| <1000 | 497 (6.6) | 150 (13.4) | 347 (5.4) | |
| 1000–1999 | 1379 (18.3) | 382 (34.0) | 997 (15.5) | |
| 2000–2999 | 2256 (29.9) | 323 (28.8) | 1933 (30.1) | |
| ≥3000 | 3412 (45.2) | 266 (23.7) | 3146 (48.9) | |
| Female sex, n, % | 3313 (43.9) | 520 (46.4) | 2793 (43.5) | .068 |
| Maternal race/ethnicity, n, % | <.001 | |||
| African American | 4136 (54.8) | 548 (48.9) | 3588 (55.8) | |
| White | 2186 (29.0) | 438 (39.1) | 1748 (27.2) | |
| Hispanic | 435 (5.8) | 56 (5.0) | 379 (5.9) | |
| Other/unknown | 792 (10.5) | 79 (7.1) | 713 (11.1) | |
| Maternal age (y), median, IQR | 28 (22–33) | 30 (25–35) | 27 (22–32) | <.001 |
| 5-min Apgar score <5, n, % | 331 (4.4) | 65 (5.8) | 266 (4.1) | .004 |
| Length of stay (d), median, IQR | 6 (3–18) | 15 (5–40) | 5 (3–15) | <.001 |
| Early-onset sepsis, n, % | 41 (0.54) | 0 | 41 (0.64) | .003 |
| Antibiotics in first 72 h, n, % | 6754 (89.5) | 901 (80.4) | 5853 (91.1) | <.001 |
| Antibiotic duration, hours, median, IQR | 39 (37–59)b | 47 (37–62)c | 38 (37–51)d | <.001 |
| Prolonged antibiotics, n, % | 1241 (18.5)b | 203 (22.5)c | 1038 (17.9)d | .001 |
BW, birth weight; g, grams; GA, gestational age; IQR, interquartile range.
a
Missing data are present for the following characteristics: gestational age (n = 6), birth wt (n = 5), maternal age (n = 214), 5-min Apgar score (n = 74).
b
Denominator (6713) includes infants started on antibiotics in the first 72 h without EOS.
c
Denominator (901) includes infants started on antibiotics in the first 72 h without EOS.
d
Denominator (5812) includes infants started on antibiotics in the first 72 h without EOS.