Table 2:
Infant and maternal characteristics and process measures
| Characteristic | Study year; no. (%) of infants* | p value | ||||
|---|---|---|---|---|---|---|
|
|
|
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| Baseline n = 1422 |
Year 1 n = 1611 |
Year 2 n = 1508 |
Year 3 n = 1485 |
Overall† | Baseline v. yr 3‡ | |
| Sex, male | 778 (55) | 897 (56) | 799 (53) | 841 (57) | 0.2 | 0.3 |
|
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| Gestational age (GA) | < 0.001 | < 0.001 | ||||
|
| ||||||
| 220 to 256 wk§ | 403 (28) | 519 (32) | 477 (32) | 534 (36) | ||
|
| ||||||
| 260 to 286 wk§ | 1019 (72) | 1092 (68) | 1031 (68) | 951 (64) | ||
|
| ||||||
| Mean ± SD, wk | 26.3 ± 1.5 | 26.2 ± 1.5 | 26.2 ± 1.5 | 26.1 ± 1.5 | < 0.001 | < 0.001 |
|
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| Birth weight, g, mean ± SD | 947 ± 274 | 920 ± 238 | 919 ± 246 | 919 ± 256 | 0.004 | 0.004 |
|
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| Small for GA | 130 (9) | 133 (8) | 121 (8) | 19 (8) | 0.6 | 0.3 |
|
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| Outborn¶ | 304 (21) | 304 (19) | 284 (19) | 283 (19) | 0.2 | 0.1 |
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| Apgar score < 7 at 5 min | 543 (38) | 618 (38) | 628 (42) | 675 (45) | < 0.001 | < 0.001 |
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| SNAP-II score > 20 | 393 (28) | 475 (29) | 457 (30) | 476 (32) | 0.05 | 0.006 |
|
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| Singleton | 1012 (71) | 1153 (72) | 1090 (72) | 1089 (73) | 0.6 | 0.2 |
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| Cesarean birth | 801 (56) | 910 (56) | 842 (56) | 833 (56) | 0.9 | 0.6 |
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| Maternal hypertension** | 203/1391 (15) | 245/1560 (16) | 238/1483 (16) | 211/1436 (15) | 0.6 | 0.9 |
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| Maternal diabetes mellitus** | 96/1389 (7) | 106/1531 (7) | 116/1454 (8) | 108/1415 (8) | 0.6 | 0.5 |
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| Antenatal steroids** | 1151/1374 (84) | 1358/1562 (87) | 1264/1465 (86) | 1258/1458 (86) | 0.08 | 0.06 |
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| Intrapartum magnesium sulphate** | NA | 194/1133 (17) | 320/1437 (22) | 582/1419 (41) | < 0.001 | NA |
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| Surfactant use | 1115 (78) | 1271 (79) | 1182 (78) | 1126 (76) | 0.2 | 0.1 |
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| Age at first surfactant, median (IQR), min | 31 (15–93) | 39 (17–161) | 44 (19–201) | 46 (20–212) | < 0.001 | 0.02 |
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| Mechanical ventilation, any time | 1260 (89) | 1391 (86) | 1268 (84) | 1228 (83) | < 0.001 | < 0.001 |
Note: EPIQ = Evidence-based Practice for Improving Quality, IQR = interquartile range, NA = not available, SD = standard deviation, SNAP-II = Score for Neonatal Acute Physiology, version II (a measure of severity of illness on admission to neonatal intensive care unit; scores range from 0 to 115, with higher scores indicating increasing sickness).21
Except where indicated otherwise.
Calculated using χ2 test for categorical variables and F test or Wilcoxon rank-sum test, as appropriate, for continuous variables.
Based on comparison between baseline and year 3.
Superscript 0 and 6 denote number of days in addition to weeks of gestation.
Born at a hospital other than the institution that housed the admitting neonatal intensive care unit.
Data missing for some infants; denominators used to calculate percentages (shown in these rows) reflect available data.