Baseline characteristics of patients
| Characteristic | Total (n=1740) | Inpatients (n=1131) | Outpatients (n=609) | p Value* |
| Mean±SD age (years) | 60±18 | 64±18 | 51±16 | <0.0001 |
| Male sex, n (%) | 961 (55.2) | 682 (60.3) | 279 (45.8) | <0.0001 |
| Smokers, n (%) | 513 (29.5) | 329 (29.1) | 184 (30.2) | 0.6 |
| Comorbidities, n (%) | ||||
| Congestive heart failure | 298 (17.1) | 262 (23.2) | 36 (5.9) | <0.0001 |
| COPD | 610 (35.1) | 432 (38.2) | 178 (29.2) | 0.0002 |
| Chronic renal disease | 141 (8.1) | 132 (11.7) | 9 (1.5) | 0.0001 |
| Chronic liver disease | 57 (3.3) | 41 (3.7) | 16 (2.6) | 0.3 |
| Cerebrovascular disease | 165 (9.5) | 157 (13.9) | 8 (1.3) | <0.0001 |
| Malignancy | 166 (9.5) | 128 (11.3) | 38 (6.2) | 0.0006 |
| Diabetes mellitus | 286 (16.4) | 247 (21.9) | 39 (6.4) | <0.0001 |
| Physical examination findings, n (%) | ||||
| Confusion | 143 (8.2) | 132 (11.7) | 11 (1.8) | <0.0001 |
| Respiratory rate ≥ 30/min | 146 (8.4) | 127 (11.2) | 19 (3.1) | 0.0001 |
| Blood pressure systolic <90 mm Hg or diastolic ≤60 mm Hg | 311 (17.9) | 251 (22.2) | 60 (9.9) | <0.0001 |
| Aetiology of CAP, n (%) | ||||
| Typical bacterial pathogens† | 100 (5.7) | 74 (6.5) | 26 (4.3) | 0.05 |
| Atypical pathogens‡ | 170 (9.8) | 100 (9.6) | 61 (10.0) | 0.4 |
| Viruses§ | 21 (1.2) | 13 (1.1) | 8 (1.3) | 0.8 |
| Mixed¶ | 40 (2.3) | 31 (2.7) | 9 (1.5) | 0.09 |
| Unknown | 1409 (81.0) | 904 (79.9) | 505 (82.9) | 0.1 |
| Prior antibiotics, n (%) | 480 (27.6) | 279 (24.7) | 201 (33.0) | 0.0002 |
| CRB-65, n (%) | ||||
| 0 | 726 (41.7) | 354 (31.3) | 372 (61.1) | <0.0001 |
| 1 | 717 (41.2) | 506 (44.7) | 211 (34.6) | <0.0001 |
| 2 | 232 (13.3) | 207 (18.3) | 25 (4.1) | <0.0001 |
| 3 | 58 (3.3) | 57 (5.0) | 1 (0.2) | <0.0001 |
| 4 | 7 (0.4) | 7 (0.6) | 0 (0) | 0.05 |
| 28-day mortality, n (%) | 78 (4.5) | 77 (6.9) | 1 (0.2) | <0.0001 |
| Cumulative 180-day mortality, n (%) | 171 (9.9) | 167 (14.8) | 4 (0.7) | <0.0001 |
↵* Comparison of inpatients vs outpatients.
↵† S pneumoniae, H influenzae, E coli, S aureus, Moraxella catarrhalis, Enterobacter spp, Proteus mirabilis, Pseudomonas spp, Citrobacter spp, Enterococcus faecium, Klebsiella pneumoniae, Streptococcus agalactiae.
↵‡ Mycoplasma pneumoniae, Legionella pneumophila, Chlamydophila pneumoniae.
↵§ Influenza A, respiratory syncytial virus.
↵¶ Infections with two or more pathogens including the following combinations: two or more typical or atypical bacteria, typical bacterial plus atypical bacterial infection, typical or atypical bacterial infection plus viruses.
CAP, community-acquired pneumonia; COPD, chronic obstructive pulmonary disease.