Parameter | Case (%), (n=230) | Control (%), (n=230) | Total (%), (N=460) |
Demographic and clinical data | |||
Age | |||
≤12 months | 21 (9.1) | 23 (10) | 44 (9.5) |
1–5 years | 126 (54.7) | 157 (68.2) | 283 (61.5) |
6–9 years | 60 (26.1) | 27 (11.7) | 87 (18.9) |
10+ years | 23 (10) | 23 (10) | 46 (10) |
Male sex | 120 (52.1) | 122 (53.0) | 242 (52.6) |
Aboriginal* | 21 (9.1) | 2 (0.8) | 23 (5.0) |
Premature* | 32 (13.9) | 17 (7.3) | 49 (10.6) |
Smoker at household* | 38 (16.5) | 22 (9.5) | 60 (13.0) |
Existing health conditions† | |||
Any comorbidity | 34 (14.7) | 10 (4.3) | 44 (9.5) |
Immunodeficiency | 7 (3.0) | 1 (0.4) | 8 (1.7) |
Immunocompromised condition | 5 (2.1) | 0 (0.0) | 5 (1.1) |
Congenital chromosomal abnormality | 16 (6.9) | 4 (1.7) | 20 (4.3) |
Chronic respiratory illness | 9 (3.9) | 2 (0.8) | 11 (2.3) |
Chronic neuromuscular disorder illness | 9 (3.9) | 2 (0.8) | 11 (2.3) |
*P value <0.001 for difference between cases and controls.
†No child had an organ transplant, one case had chronic cardiac disease and one case had an intracranial shunt.