Table 5 Subgroup analysis of the effect of rhEPO on confirmed NEC
| Â | Control n/total (%) | rhEPO n/total (%) | p-value | Relative risk [95% CI] | Interaction p | Total n/total (%) |
|---|---|---|---|---|---|---|
Gestation age | ||||||
 < 28 w | 9/53 (17.0) | 2/57 (3.5) | 0.019 | 0.178 [0.037–0.865] |  | 11/110 (10.0) |
 28–296/7 w | 14/258 (5.4) | 7/288 (2.4) | 0.069 | 0.434 [0.172–1.093] |  | 21/546 (3.8) |
 30–32 w | 12/333 (3.6) | 10/296 (3.4) | 0.878 | 0.935 [0.398–2.198] | 0.013 | 22/629 (3.5) |
Birth weight | ||||||
 < 1000 g | 12/54 (22.2) | 2/50 (4.0) | 0.007 | 0.146 [0.031–0.689] |  | 14/104 (13.5) |
 1000–1499 g | 19/432 (4.4) | 10/462 (2.2) | 0.060 | 0.481 [0.221–1.046] |  | 29/894 (3.2) |
 ≥ 1500 g | 4/158 (2.5) | 7/129 (5.4) | 0.204 | 2.209 [0.632–7.720] | 0.142 | 11/287 (3.8) |
Delivery mode | ||||||
 Vaginal delivery | 15/260 (5.8) | 4/240 (1.7) | 0.017 | 0.277 [0.091–0.846] |  | 19/500 (3.8) |
 Caesarean | 20/384 (5.2) | 15/401 (3.7) | 0.319 | 0.707 [0.357–1.402] | 0.154 | 35/785 (4.5) |
Gender | ||||||
 Girl | 12/259 (4.6) | 4/267 (1.5) | 0.036 | 0.343 [0.108–1.091] |  | 16/526 (3.0) |
 Boy | 23/385 (6.0) | 15/374 (4.0) | 0.215 | 0.647 [0.332–1.260] | 0.267 | 38/759 (5.0) |
Mechanical ventilation | ||||||
 < 7 days | 28/577 (4.9) | 17/553 (3.1) | 0.126 | 0.622 [0.336–1.149] |  | 45/1130 (4.0) |
 ≥ 7 days | 7/67 (10.4) | 2/88 (2.3) | 0.031 | 0.199 [0.040–0.993] | 0.181 | 9/155 (5.8) |
1Â min Apgar score | ||||||
 > 3 | 32/614 (5.2) | 19/617 (3.1) | 0.061 | 0.578 [0.324–1.031] |  | 51/1231 (4.1) |
 ≤ 3 | 3/30 (10.0) | 0/24 (0.0) | 0.111 | 0.900 [0.799–1.014] | 0.226 | 3/54 (5.6) |
5Â min Apgar score | ||||||
 > 5 | 34/622 (5.5) | 19/608 (3.1) | 0.060 | 0.558 [0.315–0.989] |  | 53/1230 (4.3) |
 ≤ 5 | 1/22 (4.5) | 0/33 (0.0) | 0.400 | 0.389 [0.278–0.543] | 0.053 | 1/55 (1.8) |
Hemoglobin | ||||||
 ≥ 90 g/l | 11/296 (3.7) | 7/301 (2.3) | 0.320 | 0.617 [0.236–1.614] |  | 18/597 (3.0) |
 < 90 g/l | 24/348 (6.9) | 12/340 (3.5) | 0.047 | 0.494 [0.243–1.004] | 0.715 | 36/688 (5.2) |