Clinical course of influenza illness and major complications according to the results of influenza A/H1N1 testing
| A/H1N1+ve (n=68) | A/H1N1–ve (n=59) | All patients | RR (95% CI) | p | |
| Duration of disease (days)* | 5 (3–11) | 10 (6–14) | 7 (4–14) | – | 0.002 |
| Pulmonary exacerbation† | 46 (67.6%) | 47 (79.7%) | 93 (73.2%) | 0.85 (0.69–1.05) | 0.127 |
| Hospitalisation | 47 (69.1%) | 41 (69.5%%) | 88 (69.3%) | 1.00 (0.79–1.25) | 1.000 |
| Antiviral therapy‡ | 56 (82.4%) | 7 (11.1%) | 63 (49.6%) | – | <0.0001 |
| Complications | 10 (14.7%) | 7 (11.9%) | 17 (13.4%) | 1.24 (0.50–3.05) | 0.795 |
| Permanent need for oxygen therapy | 1 (1.5%) | 0 | 1 (0.8%) | – | – |
| Respiratory failure | 1 (1.5%) | 1 (1.7%) | 2 (1.6%) | – | – |
| Pneumothorax | 1 (1.5%) | 0 | 1 (0.8%) | – | – |
| Haemoptysis | 2 (3.0%) | 2 (3.4%) | 4 (3.1%) | – | – |
| Atelectasia | 0 | 1 (1.7%) | 1 (0.8%) | – | – |
| Death | 3 (4.4%) | 1 (1.7%) | 4 (3.1%) | 2.60 (0.28–24) | – |
↵* Among the 68 patients with A/H1N1 infection, duration of disease was 5 (3–9) days in the 56 patients treated with oseltamivir and 5 (3–11) days in the 12 patients who did not receive antiviral treatment (p=0.874).
↵† Among the 68 patients with A/H1N1 infection, pulmonary exacerbations occurred in 69.6% of patients treated with oseltamivir and in 58.3% of those who did not receive antiviral therapy (p=0.505).
↵‡ Among the 68 patients with A/H1N1 infection, complications occurred in 17.9% of patients treated with oseltamivir and in none of those who did not receive antiviral therapy (p=0.189).