Table 4 Subgroup analysis the effect of rhEPO on all stages NEC
| Â | Control n/total (%) | rhEPO n/total (%) | p-value | Relative risk [95% CI] | Interaction p | Total n/total (%) |
|---|---|---|---|---|---|---|
Gestation age | ||||||
 < 28w | 11/53 (20.8) | 8/57 (14.0) | 0.352 | 0.623 [0.229–1.694] |  | 19/110 (17.3) |
 28–296/7w | 49/258 (19.0) | 33/288 (11.5) | 0.014 | 0.552 [0.342–0.890] |  | 82/546 (15,0) |
 30–32w | 50/333 (15.0) | 36/296 (12.2) | 0.299 | 0.784 [0.495–1.242] | 0.581 | 86/629 (13.7) |
Birth weight | ||||||
 < 1000 g | 18/54 (33.3) | 5/50 (10.0) | 0.004 | 0.222 [0.075–0.657] |  | 23/104 (22.1) |
 1000–1499 g | 70/432 (16.2) | 54/462 (11.7) | 0.051 | 0.684 [0.467–1.003] |  | 124/894 (13.9) |
 ≥ 1500 g | 22/158 (13.9) | 18/129 (14.0) | 0.994 | 1.002 [0.512–1.962] | 0.060 | 40/287 (13.9) |
Delivery mode | ||||||
 Vaginal delivery | 39/260 (15.0) | 26/240 (1.7) | 0.166 | 0.688 [0.405–1.170] |  | 65/500 (13.0) |
 Caesarean | 71/384 (18.5) | 51/401 (12.7) | 0.026 | 0.642 [0.435–0.949] | 0.837 | 122/785 (15.5) |
Gender | ||||||
 Girl | 41/259 (15.8) | 27/267 (10.1) | 0.051 | 0.598 [0.356–1.051] |  | 68/526 (12.9) |
 Boy | 69/385 (17.9) | 50/374 (13.4) | 0.085 | 0.707 [0.476–1.050] | 0.616 | 119/759 (15.7) |
Mechanical ventilation | ||||||
 < 7 days | 85/577 (14.7) | 62/553 (11.2) | 0.079 | 0.731 [0.515–1.038] |  | 147/1130 (13.0) |
 ≥ 7 days | 25/67 (37.3) | 15/88 (17.0) | 0.004 | 0.345 [0.164–0.727] | 0.072 | 40/155 (25.8) |
1Â min Apgar score | ||||||
 > 3 | 105/614 (17.1) | 76/617 (12.3) | 0.018 | 0.681 [0.495–0.937] |  | 181/1231 (14.7) |
 ≤ 3 | 5/30 (16.7) | 1/24 (4.2) | 0.146 | 0.217 [0.024–2.003] | 0.299 | 6/54 (11.1) |
5Â min Apgar score | ||||||
 > 5 | 104/622 (17.3) | 74/608 (12.2) | 0.028 | 0.690 [0.500–0.952] |  | 178/1230 (14.5) |
 ≤ 5 | 6/22 (27.3) | 3/33 (9.1) | 0.134 | 0.267 [0.059–1.211] | 0.012 | 9/55 (16.4) |
Hemoglobin | ||||||
 ≥ 90 g/l | 31/296 (10.5) | 36/301 (12,0) | 0.565 | 1.161 [0.698–1.933] |  | 67/597 (11.2) |
 < 90 g/l | 79/348 (22.7) | 41/340 (12.1) | 0.000 | 0.467 [0.309–0.705] | 0.006 | 120/688 (17.4) |