| Factor | Log-rank statistics | Degree of Freedom | P-value |
| Sex of newborn | 1.86 | 1 | 0.173 |
| Weight of newborn | 21 | 2 | 0.000 |
| Gestational Age | 32.51 | 2 | 0.000 |
| Mode of Delivery | 0.44 | 1 | 0.506 |
| Resident Type | 9.35 | 1 | 0.002 |