Table 2.
Odds ratios and population attributable fractions for ALRI hospitalisation before age 2 years in non-Aboriginal children
| Risk factor | Univariatea | Adjusted | Adjusted | |||
|---|---|---|---|---|---|---|
| OR | 95% CI | OR | 95% CI | PAF % | 95% CI | |
| Gender | ||||||
| Female | Reference | |||||
| Male | 1.39 | 1.34, 1.45 | 1.40 | 1.34, 1.47 | 16.0 | 13.8, 18.1 |
| Gestational age | ||||||
| ≥37 weeks | Reference | |||||
| 35-36 weeks | 1.87 | 1.74, 2.02 | 1.70 | 1.54, 1.87 | 2.6 | 2.0, 3.1 |
| 33-34 weeks | 2.18 | 1.91, 2.49 | 2.04 | 1.73, 2.42 | 1.0 | 0.7, 1.3 |
| <33 weeks | 4.84 | 4.35, 5.38 | 4.70 | 4.08, 5.41 | 2.7 | 2.3, 3.1 |
| Percent optimal birthweight | ||||||
| Low <85% | 1.37 | 1.29, 1.46 | 1.14 | 1.06, 1.22 | 1.5 | 0.6, 2.3 |
| Normal 85-114% | Reference | |||||
| High ≥115% | 1.02 | 0.96, 1.09 | 1.02 | 0.95, 1.11 | 0.3 | -0.5, 1.0 |
| Number of previous pregnancies | ||||||
| 0 | Reference | |||||
| 1 | 1.47 | 1.40, 1.56 | 1.63 | 1.52, 1.74 | 11.3 | 9.7, 12.8 |
| 2 | 1.73 | 1.64, 1.84 | 2.00 | 1.86, 2.17 | 10.6 | 9.4, 11.8 |
| ≥3 | 2.12 | 2.00, 2.24 | 2.47 | 2.29, 2.66 | 15.4 | 14.1, 17.0 |
| Season of birth | ||||||
| Spring | Reference | |||||
| Summer | 1.23 | 1.16, 1.30 | 1.24 | 1.16, 1.33 | 4.2 | 2.8, 5.6 |
| Autumn | 1.64 | 1.56, 1.73 | 1.72 | 1.61, 1.83 | 12.3 | 10.8, 13.8 |
| Winter | 1.39 | 1.31, 1.47 | 1.41 | 1.32, 1.51 | 7.0 | 5.6, 8.4 |
| Mode of delivery | ||||||
| Vaginal | 1.40 | 1.31, 1.49 | 1.04 | 0.96, 1.13 | 2.2 | -2.2, 6.5 |
| Instrumental | Reference | |||||
| Elective caesarean | 1.48 | 1.38, 1.60 | 1.34 | 1.22, 1.48 | 4.1 | 2.8, 5.3 |
| Emergency caesarean | 1.52 | 1.41, 1.65 | 1.20 | 1.09, 1.33 | 2.0 | 0.9, 3.1 |
| Maternal smoking during pregnancy | ||||||
| No | Reference | |||||
| Yes | 1.79 | 1.70, 1.89 | 1.33 | 1.26, 1.41 | 6.3 | 5.0, 7.6 |
| Maternal asthma during pregnancy | ||||||
| No | Reference | |||||
| Yes | 1.64 | 1.55, 1.74 | 1.47 | 1.37, 1.57 | 4.6 | 3.7, 5.5 |
| Maternal age (years) | ||||||
| ≥35 years | Reference | |||||
| 30-34 years | 1.10 | 1.04, 1.18 | 1.21 | 1.12, 1.31 | 4.6 | 2.8, 6.4 |
| 25-29 years | 1.31 | 1.23, 1.39 | 1.52 | 1.41, 1.65 | 10.2 | 8.4, 12.0 |
| 20-24 years | 1.73 | 1.62, 1.84 | 1.97 | 1.80, 2.15 | 9.6 | 8.4, 10.8 |
| <20 years | 1.97 | 1.80, 2.15 | 2.60 | 2.30, 2.94 | 3.8 | 3.2, 4.4 |
| SEIFA Index of Disadvantageb | ||||||
| 91-100% | Reference | |||||
| 76-90% | 1.23 | 1.11, 1.36 | 1.12 | 0.99, 1.25 | 1.2 | -0.1, 2.5 |
| 26-75% | 1.47 | 1.35, 1.61 | 1.10 | 0.99, 1.22 | 4.2 | -0.2, 8.5 |
| 11-25% | 1.92 | 1.74, 2.11 | 1.28 | 1.14, 1.43 | 4.3 | 2.4, 6.1 |
| 0-10% | 2.23 | 2.01, 2.47 | 1.33 | 1.17, 1.50 | 2.8 | 1.6, 3.9 |
| Accessibility/Remoteness Index of Australia | ||||||
| Very remote | Reference | |||||
| Remote | 1.47 | 1.16, 1.87 | 1.36 | 1.03, 1.81 | 1.2 | 0.2, 2.1 |
| Outer regional | 1.89 | 1.51, 2.37 | 1.62 | 1.25, 2.12 | 4.6 | 2.5, 6.8 |
| Inner regional | 1.31 | 1.04,1.64 | 1.05 | 0.81, 1.38 | 0.5 | -2.1, 3.1 |
| Major cities | 1.23 | 0.99, 1.53 | 1.14 | 0.88, 1.48 | 8.4 | -8.1, 22.4 |
aall adjusted for birth year
b 91-100% is least disadvantaged and 0-10% is most disadvantaged.