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) | |
*IRR, incidence rate ratio.
**91-100% is least disadvantaged and 0-10% is most disadvantaged.