| Baseline characteristics and comorbidities | Study population | CURB-65 0–1 | p-value# | |
| Discharged from hospital in ≤12 h | Admitted to hospital for >12 h | |||
| Subjects n | 1472 | 145 | 420 | |
| Age yrs | 69 (54–79) | 50 (38–68) | 58 (41–68) | 0.2 |
| Males | 49.9 | 52.3 | 53.6 | 0.9 |
| Chronic cardiac disease | 20.6 | 4.8 | 13.1 | 0.01 |
| Liver disease | 5.1 | 3.4 | 6.7 | 0.2 |
| Neurological disease | 11.8 | 3.4 | 7.1 | 0.2 |
| Chronic renal failure | 6.3 | 1.4 | 1.4 | 0.9 |
| Diabetes mellitus | 10.9 | 5.5 | 4.5 | 0.8 |
| COPD | 22.3 | 9.0 | 21.2 | 0.02 |
| Current smokers | 34.2 | 38.6 | 35.7 | 0.6 |
Data are presented as median (interquartile range) or %, unless otherwise stated. CURB-65: confusion, urea >7 mmol·L−1, respiratory frequency ≥30 breaths·min−1, systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg, and age ≥65 yrs; COPD: chronic obstructive pulmonary disease. #: p-value refers to comparison between CURB-65 0–1 groups.