| Presenting with respiratory failure | Presenting without respiratory failure | p-value | |
| Subjects n | 615 | 643 | |
| Sociodemographic and temporal variables | |||
| Age years | 62.13 | 55.42 | <0.001 |
| Male | 411/615 (66.9) | 388/615 (60.4) | 0.019 |
| Period of influenza epidemic | 155/513 (25.2) | 169/643 (26.3) | ns |
| Previous pneumococcal vaccination | 124/513 (24.1) | 96/561 (17.1) | 0.015 |
| Smoking | 341/607 (56.2) | 349/631 (55.3) | ns |
| Heavy alcohol consumption | 127/605 (21) | 101/629 (16.1) | 0.028 |
| Underlying disease | |||
| Chronic lung disease | 216/607 (35.6) | 144/631 (22.8) | <0.001 |
| Chronic heart disease | 140/605 (23.1) | 76/623 (12.2) | <0.001 |
| Cerebrovascular disease | 75/605 (12.4) | 40/623 (6.4) | 0.001 |
| HIV infection | 94/611 (15.4) | 124/638 (19.4) | 0.063 |
| Haematological cancer | 46/610 (7.5) | 47/638 (7.4) | ns |
| Solid cancer | 84/610 (13.8) | 68/638 (10.3) | 0.068 |
| Clinical presentation and outcomes | |||
| Bilateral pneumonia | 210/614 (34.2) | 63/643 (9.8) | <0.001 |
| Bilobar or multilobar pneumonia | 347/614 (58.2) | 109/643 (17) | <0.001 |
| Septic shock | 254/609 (41.7) | 39/638 (6.1) | <0.001 |
| ICU admission | 234/609 (38.4) | 27/638 (4.2) | <0.001 |
| PSI ≥4# | 533/609 (87.6) | 328/638 (51.4) | <0.001 |
| Mechanical ventilation | 161/609 (26.1) | 15/639 (2.3) | <0.001 |
| Length of hospital stay days | 17.83 | 10.62 | <0.001 |
| Empyema | 120/615 (19.5) | 120/643 (18.7) | ns |
| Hospital mortality | 157/615 (25.5) | 23/643 (3.5) | <0.001 |
| Microbiological data | |||
| Serotype 1 | 42/480 (8.8) | 98/543 (18) | <0.001 |
| Serotype 3 | 79/480 (16.5) | 41/523 (7.6) | <0.001 |
| Serotype 7F | 27/480 (5.6) | 45/523 (8.3) | 0.111 |
| Serotype 8 | 25/480 (5.2) | 30/523 (5.4) | 0.467 |
| Serotype 19A | 38/480 (7.9) | 20/523 (3.7) | 0.004 |
| Serotype 19F | 22/480 (4.6) | 5/523 (0.9) | <0.001 |
| Serotype 23A | 2/480 (0.4) | 9/523 (1.7) | 0.07 |
| Serotype 23F | 5/480 (1) | 16/523 (2.9) | 0.045 |
| Penicillin susceptibility¶ | 600/615 (97.5) | 633/643 (98.5) | ns |
| Cephalosporin susceptibility+ | 601/615 (97.7) | 624/643 (97) | ns |
Data are presented as mean or n/N (%), unless otherwise stated. ICU: intensive care unit; PSI: pneumonia severity index; ns: nonsignificant. #: PSI score ≥4 at the moment of admission to the emergency department; ¶: includes isolates with minimum inhibitory concentration (MIC) ≤2 μg·mL−1; +: includes isolates with MIC ≤1 μg·mL−1.