Univariate analyses of covariates for severe ROP development in infants with a BW≤1500 g
| Covariates | Infants BW≤1500 g | Univariate analysis (Severe ROP vs No ROP) | |||
| No ROP (n=2022) | Severe ROP (n=395) | P value | 95% CI | OR | |
| Maternal age (years)* | 28.9±6.4 | 28.7±6.2 | 0.565 | 0.979 to 1.012 | 0.995 |
| Antenatal steroid, two doses | 870 (43%) | 145 (36.7 %) | 0.02‡ | 0.614 to 0.959 | 0.767 |
| Preeclampsia | 544 (26 %) | 83 (21%) | 0.015‡ | 0.556 to 0.938 | 0.722 |
| Gestational diabetes | 106 (5 %) | 23 (5.8 %) | 0.640 | 0.702 to 1.777 | 1.117 |
| Chorioamnionitis | 165 (8 %) | 56 (14 %) | <0.001‡ | 1.343 to 2.570 | 1.858 |
| IVF pregnancy | 247 (12%) | 41 (10 %) | 0.832 | 0.586 to 1.180 | 0.832 |
| Multiple births | |||||
| Twins | 424 (21%) | 80 (20.3 %) | 0.728 | 0.729 to 1.248 | 0.953 |
| Triplets | 76 (3.8 %) | 14 (3.5%) | 0.810 | 0.519 to 1.668 | 0.931 |
| Vaginal delivery | 236 (12 %) | 83 (21 %) | <0.001‡ | 1.524 to 2.656 | 2.012 |
| Gestational age (weeks)* | 29.8±2.2 | 26.5±1.9 | <0.001‡ | 0.441 to 0.511 | 0.475 |
| BW (g)* | 1215±215 | 888±228 | <0.001‡ | 0.994 to 0.995 | 0.994 |
| Male gender | 934 (46 %) | 207 (52 %) | 0.028‡ | 1.035 to 1.593 | 1.284 |
| SGA | 520 (25.7 %) | 50 (12.7 %) | <0.001‡ | 0.306 to 0.572 | 0.418 |
| Resuscitation at birth | 853 (42 %) | 306 (77 %) | <0.001‡ | 3.667 to 6.070 | 4.717 |
| RDS | 1228 (83 %) | 361 (91 %) | <0.001 | 4.820 to 9.957 | 6.928 |
| Surfactant treatment | 959 (47 %) | 340 (86 %) | <0.001‡ | 5.092 to 9.240 | 6.859 |
| Duration of invasive mechanical ventilation (days)† | 0±2 (0–148) | 17±40 (0–308) | <0.001‡ | 1.063 to 1.080 | 1.071 |
| Duration of noninvasive ventilation (days)† | 3±7 (0–87) | 18±22 (0–120) | <0.001‡ | 1.079 to 1.100 | 1.090 |
| Total days on oxygen† | 10±23 (0–171) | 65±53 (0–308) | <0.001‡ | 1.047 to 1.057 | 1.052 |
| PDA requiring treatment | 349 (36 %) | 210 (53 %) | <0.001‡ | 4.326 to 6.837 | 5.438 |
| Intracranial haemorrhage (>Grade II) | 73 (3.6 %) | 70 (17.7 %) | <0.001‡ | 4.057 to 8.142 | 5.748 |
| Early-onset neonatal sepsis | 433 (21 %) | 167 (42 %) | <0.001‡ | 2.149 to 3.378 | 2.694 |
| Late-onset neonatal sepsis | 677 (33 %) | 294 (74 %) | <0.001‡ | 4.537 to 7.394 | 5.792 |
| NEC (≥Stage II) | 142 (7 %) | 84 (21 %) | <0.001‡ | 2.680 to 4.840 | 3.601 |
| BPD | 273 (13 %) | 266 (67 %) | <0.001 | 10.324 to 16.884 | 13.203 |
| Frequency of RBC transfusions | |||||
| Once | 426 (21 %) | 41 (10%) | <0.001‡ | 2.637 to 7.503 | 4.448 |
| Twice and more | 532 (26 %) | 331 (83%) | <0.001‡ | 18.607 to 44.438 | 28.756 |
| Breastfeeding more than 80% of feeding at PN 28 days, (n, %) | 1347 (66 %) | 162 (41 %) | <0.001‡ | 0.279 to 0.434 | 0.348 |
| Age of regain BW (days)* | 11.3±5.1 | 14.5±6 | <0.001‡ | 1.080 to 1.121 | 1.100 |
| Relative weight gain at 28 days (g)* | 382±180 | 229±135 | <0.001‡ | 0.993 to 0.995 | 0.994 |
*The values are presented as mean±SD.
†The values are presented as median±IQR, min-max values are given in parentheses.
‡The variables that were put in the logistic regression model.
BPD, bronchopulmonary dysplasia; BW, birth weight; IVF, in vitro fertilisation; n, number of patients; NEC, necrotising enterocolitis; p, significant difference between patients with severe ROP versus those with no ROP, defined as p<0.05; PDA, patent ductus arteriosus; PN, postnatal; RBC, red blood cell ; RDS, respiratory distress syndrome; ROP, retinopathy of prematurity; SGA, small for gestational age.