Univariate analysis with NEC as outcome
| Risk factors* | NEC n=174 | No NEC n=2886 | RR (95% CI) | p Value |
|---|---|---|---|---|
| Apgar score 5 min | 7 (2) | 7 (2) | 0.997 (0.913 to 1.088) | 0.7 |
| Gender, male % | 55.8 | 48.3 | 1.32 (0.99 to 1.77) | 0.057 |
| Race, AA % | 85.1 | 80.3 | 1.37 (0.91 to 2.06) | 0.12 |
| Birth weight (g) | 924 (429) | 1042 (492) | 0.9998 (0.9988 to 0.9998) | <0.01 |
| Gestational age (weeks) | 27 (4) | 28 (5) | 0.89 (0.85 to 0.94) | <0.01 |
| Small for gestational age | 35.1% | 37.4% | 0.90 (0.67 to 1.23) | 0.54 |
| Umbilical artery catheter days | 4 (10) | 2 (8) | 1.031 (1.009 to 1.054) | <0.01 |
| Days on ventilator | 7 (16) | 2 (13) | 1.012 (1.004 to 1.020) | <0.01 |
| Treatment for PDA | 25.30% | 24.60% | 1.033 (0.74 to 1.44) | 0.85 |
| Study period 2004–2011 (n) | 87 | 1473 | 1.021 (0.88 to 1.19) | 0.79 |
| Number of transfusions | 6 (8) | 5 (8) | 1.060 (1.039 to 1.080) | 0.017 |
| Exposure to blood transfusion (%) | 66.7% | 59.8% | 1.32 (0.97 to 1.80) | 0.073 |
*Presented as the percentage of the number of infants or as median (IQR).
AA, African-American; NEC, necrotising enterocolitis; PDA, patent ductus arteriosus.