Univariate analysis: perinatal variables not associated with chronic lung disease 1998–1999
| Perinatal variable | Unadjusted OR (95% CI) | p Value | Missing data |
|---|---|---|---|
| OR, Odds ratio; CI, confidence interval. | |||
| Maternal age | 0.41 | 0 | |
| ⩾35 years | 1.07 (0.92 to 1.26) | ||
| 20–34 years | 1.00 reference group | ||
| <20 years | 0.91 (0.73 to 1.13) | ||
| Previous preterm birth | 1.02 (0.85 to 1.22) | 0.85 | 672 |
| Prolonged rupture of membranes (>24 h) | 0.99 (0.85 to 1.16) | 0.93 | 428 |
| Preterm labour | 0.93 (0.81 to 1.06) | 0.25 | 6 |
| Maternal corticosteroids (any dose) | 1.19 (0.99 to 1.43) | 0.06 | 218 |
| Fetal distress requiring intervention | 1.12 (0.95 to 1.32) | 0.17 | 518 |
| Plurality | 1.00 | 0 | |
| Singleton | 1.00 reference group | ||
| Multiple pregnancy | 1.00 (0.87 to 1.15) | ||
| Birth order | 0.95 | 2 | |
| Singleton or 1st of multiple pregnancy | 1.00 reference group | ||
| 2nd or higher of multiple pregnancy | 1.00 (0.86 to 1.15) | ||
| Outborn, transferred after birth | 1.11 (0.91 to 1.37) | 0.31 | 0 |