| Control group | Intervention group | p-value | |
| Subjects# | 172 | 176 | |
| Demographics | |||
| Age years | 68.2±16.8 | 67.3±18.6 | 0.626 |
| Female | 52 (30.2) | 65 (36.9) | 0.186 |
| Nursing home resident | 24 (14.0) | 14 (8.0) | 0.076 |
| Comorbid illness | |||
| Neoplastic disease | 13 (7.6) | 21 (11.9) | 0.169 |
| Liver disease | 6 (3.5) | 7 (4.0) | 0.810 |
| Heart failure | 37 (21.5) | 19 (10.8) | 0.007 |
| Cerebrovascular disease | 51 (29.7) | 46 (26.1) | 0.465 |
| Renal disease | 34 (19.8) | 18 (10.2) | 0.013 |
| Diabetes mellitus | 67 (39.0) | 52 (29.5) | 0.064 |
| Vital signs at emergency department | |||
| Altered mental status | 55 (32.0) | 68 (38.6) | 0.194 |
| Heart rate beats·min−1 | 107.0±23.1 | 103.4±22.6 | 0.142 |
| Respiratory rate breaths·min−1 | 23.1±5.6 | 24.0±7.4 | 0.203 |
| Systolic blood pressure mmHg | 119.4±29.8 | 119.2±29.8 | 0.968 |
| Diastolic blood pressure mmHg | 62.1±16.7 | 61.4±15.5 | 0.687 |
| Temperature °C | 37.6±1.2 | 37.2±3.1 | 0.073 |
| PaO2/FIO2 ratio % | 175.5 (92.3–279.3) | 192.4 (114.0–282.1) | 0.224 |
| SpO2/FIO2 ratio % | 271.0 (99.0–426.2) | 281.1 (186.8–433.3) | 0.217 |
| Laboratory and radiological findings at the emergency department | |||
| Blood urea nitrogen mmol·L−1 | 5.8 (3.6–8.9) | 9.0 (3.8–13.9) | <0.001 |
| Sodium mmol·L−1 | 135.2±6.4 | 133.9±7.0 | 0.705 |
| Glucose mmol·L−1 | 10.0±7.3 | 9.4±5.1 | 0.384 |
| Haematocrit % | 36.4±6.0 | 36.9±6.6 | 0.524 |
| White blood cells per mm3 | 12.5±6.6 | 12.5±7.3 | 0.977 |
| Platelets per mm3 | 266 (198–345) | 226 (174–318) | 0.003 |
| Arterial pH | 7.41 (7.31–7.46) | 7.42 (7.37–7.47) | 0.052 |
| Pleural effusion | 37 (21.5) | 52 (29.5) | 0.086 |
| Multilobar infiltrates | 128 (74.4) | 145 (82.4) | 0.071 |
| Pneumonia Severity Index points | 123.8±33.5 | 116.0±35.7 | 0.038 |
| IDSA/ATS minor criteria score | 3.45±0.651 | 3.54±0.834 | 0.251 |
| Fulfilment of individual IDSA/ATS criterion for severe CAP | |||
| Respiratory rate ≥30 breaths·min−1 | 30 (17.4) | 32 (18.2) | 0.857 |
| PaO2/FIO2 ratio ≤250 | 109 (63.4) | 103 (58.5) | 0.354 |
| Multilobar infiltrates | 128 (74.4) | 145 (82.4) | 0.071 |
| Confusion/disorientation | 55 (32.0) | 68 (38.6) | 0.194 |
| Uraemia¶ | 130 (75.6) | 118 (67.0) | 0.079 |
| Leukopenia+ | 14 (8.1) | 21 (11.9) | 0.240 |
| Thrombocytopenia § | 14 (8.1) | 13 (7.4) | 0.793 |
| Hypothermiaƒ | 8 (4.7) | 12 (6.8) | 0.385 |
| Hypotension requiring aggressive fluid resuscitation | 105 (61.0) | 111 (63.1) | 0.698 |
Data are presented as n, mean±sd, n (%) or median (interquartile range), unless otherwise stated. PaO2: arterial oxygen tension; FIO2: inspiratory oxygen fraction; SpO2: arterial oxygen saturation measured by pulse oximetry; IDSA: Infectious Diseases Society of America; ATS: American Thoracic Society; CAP: community-acquired pneumonia.#: data were complete for all patients except PaO2/FIO2 ratio (37.1% missing), arterial pH (34.5% missing) and glucose (19.8% missing); ¶: blood urea nitrogen ≥20 mg·dL−1; +: white blood cell count <4000 cells per mm3; §: <100 000 platelets per mm3; ƒ: core temperature <36°C.