Table 2 Adjusted incidence rate ratio for ALRI hospitalisations among children aged <2 years according to risk factors
Risk factor | Aboriginal | Non-Aboriginal | |||
|---|---|---|---|---|---|
IRR* | (95% CI) | IRR* | (95% CI) | ||
Any birth defect | 2.3 | (1.9, 2.8) | 2.0 | (1.8, 2.2) | |
Gender | |||||
Female | Reference | Reference | |||
Male | 1.4 | (1.3, 1.5) | 1.4 | (1.3, 1.5) | |
Gestational age | |||||
≥37 weeks | Reference | Reference | |||
35-36 weeks | 1.5 | (1.3, 1.8) | 1.7 | (1.5. 1.8) | |
33-34 weeks | 1.7 | (1.3, 2.3) | 2.1 | (1.7, 2.5) | |
<33 weeks | 3.0 | (2.4, 3.9) | 4.6 | (4.0, 5.4) | |
Percent optimal birthweight | |||||
Normal 85-114% | Reference | Reference | |||
Low < 85% | 1.1 | (1.0, 1.2) | 1.2 | (1.1, 1.2) | |
High ≥ 115% | 1.0 | (0.8, 1.2) | 1.0 | (0.9, 1.1) | |
Number of previous pregnancies | |||||
0 | Reference | Reference | |||
1 | 1.0 | (0.9, 1.2) | 1.7 | (1.5, 1.8) | |
2 | 1.4 | (1.1, 1.6) | 2.1 | (1.9, 2.3) | |
≥ 3 | 1.7 | (1.5, 2.0) | 2.5 | (2.4, 2.7) | |
Season of birth | |||||
Spring | Reference | Reference | |||
Summer | 1.3 | (1.1, 1.5) | 1.2 | (1.1, 1.2) | |
Autumn | 1.4 | (1.2, 1.6) | 1.5 | (1.4, 1.6) | |
Winter | 1.3 | (1.1, 1.4) | 1.3 | (1.2, 1.4) | |
Mode of delivery | |||||
Vaginal | Reference | Reference | |||
Instrumental | 1.1 | (0.9, 1.4) | 1.0 | (0.9, 1.0) | |
Elective caesarean | 1.1 | (0.9, 1.3) | 1.3 | (1.2, 1.4) | |
Emergency caesarean | 1.1 | (0.9, 1.3) | 1.2 | (1.1, 1.2) | |
Maternal smoking during pregnancy | |||||
No | Reference | Reference | |||
Yes | 1.2 | (1.1, 1.4) | 1.3 | (1.2, 1.4) | |
Maternal asthma during pregnancy | |||||
No | Reference | Reference | |||
Yes | 1.1 | (0.9, 1.3) | 1.5 | (1.4, 1.5) | |
Maternal age | |||||
≥ 35 years | Reference | Reference | |||
30-34 years | 1.0 | (0.8, 1.3) | 1.2 | (1.1, 1.3) | |
25-29 years | 1.3 | (1.0, 1.6) | 1.6 | (1.4, 1.7) | |
20-24 years | 1.5 | (1.2, 1.9) | 2.0 | (1.8, 2.2) | |
< 20 years | 2.0 | (1.6, 2.6) | 2.7 | (2.4, 3.1) | |
SEIFA Index of disadvantage** | |||||
91-100% | Reference | Reference | |||
76-90% | 0.9 | (0.3, 2.4) | 1.1 | (1.0, 1.3) | |
26-75% | 1.5 | (0.6, 3.7) | 1.2 | (1.0, 1.3) | |
11-25% | 1.5 | (0.6, 3.8) | 1.3 | (1.2, 1.5) | |
0-10% | 1.8 | (0.7, 4.3) | 1.4 | (1.2, 1.6) | |
Accessibility/Remoteness index of Australia | |||||
Very remote | Reference | Reference | |||
Remote | 0.6 | (0.5, 0.7) | 1.5 | (1.1, 1.9) | |
Outer regional | 0.7 | (0.6, 0.8) | 1.7 | (1.3, 2.2) | |
Inner regional | 0.5 | (0.4, 0.6) | 1.1 | (0.8, 1.5) | |
Major cities | 0.5 | (0.4, 0.6) | 1.2 | (0.9, 1.6) | |