Cox proportional hazards regression (HR) Models
| Covariates | Time to PDA Closure During Treatment, HR (95%CI) |
|---|---|
| Postmenstrual age at start of treatment (days)† | 0.916 (0.804, 1.044) |
| Chronological age at start of treatment (days)† | 0.414 (0.170, 1.01) |
| Gestational age at birth (days)† | 0.979 (0.85, 1.13) |
| Maternal steroids- full course | 1.538 (0.59, 4.03) |
| Birthweight (grams)‡ | 0.99 (0.94, 1.03) |
| Weight at first treatment (grams)‡ | 0.97 (0.92, 1.02) |
†for one week increase, *50 gram increase