Aetiology of community-acquired pneumonia by site of care (number of patients with known aetiology in specific site of care)
| Aetiology | Outpatients (n=161) | Ward (n=1042) | ICU (n=260) | Total (n=1463) | p Value |
| Streptococcus pneumoniae | 56 (35) | 447 (43) | 110 (42) | 613 (42) | 0.150 |
| Haemophilus influenzae | 8 (5) | 54 (5) | 8 (3) | 70 (5) | 0.361 |
| Moraxella catarrhalis | 0 (0) | 4 (0.4) | 1 (0.4) | 5 (0.3) | 0.733 |
| Atypical bacteria* † | 58 (36) | 168 (16) | 37 (14) | 263 (18) | <0.001 |
| Legionella pneumophila | 10 (6) | 87 (8) | 21 (8) | 118 (8) | 0.650 |
| Mycoplasma pneumoniae* † | 27 (17) | 32 (3) | 6 (2) | 65 (4) | <0.001 |
| Chlamydophila pneumoniae | 10 (6) | 32 (3) | 8 (3) | 50 (3) | 0.117 |
| Coxiella burnetii* † | 11 (7) | 17 (2) | 2 (1) | 30 (2) | <0.001 |
| Virus‡ | 15 (9) | 123 (12) | 10 (4) | 148 (10) | <0.001 |
| Staphylococcus aureus | 1 (1) | 18 (2) | 6 (2) | 25 (2) | 0.429 |
| MS | 1 (1) | 9 (1) | 4 (2) | 14 (1) | 0.545 |
| MR | 0 (0) | 9 (1) | 2 (1) | 11 (1) | 0.498 |
| GNEB | 1 (1) | 23 (2) | 3 (1) | 27 (2) | 0.250 |
| Pseudomonas aeruginosa | 1 (1) | 37 (4) | 12 (5) | 50 (3) | 0.082 |
| Mixed† ‡ | 15 (9) | 135 (13) | 58 (22) | 208 (14) | <0.001 |
| Others | 6 (4) | 33 (3) | 15 (6) | 54 (4) | 0.138 |