| Patients n | 242 |
| Stable characteristics | |
| Age yrs | 69±9 |
| Males | 108 (45) |
| Height m | 1.62±0.10 |
| Current smokers | 115 (48) |
| Smoking history pack-yrs | 50 (33–63) |
| FEV1 L | 0.90 (0.68–1.20) |
| FVC L | 2.05 (1.63–2.65) |
| FEV1/FVC ratio | 44 (35–55) |
| Severity of obstruction by GOLD criteria | |
| Mild | 10 (5) |
| Moderate | 59 (32) |
| Severe | 65 (35) |
| Very severe | 52 (28) |
| Long-term oxygen therapy | 40 (17) |
| Home nebulisers | 119 (49) |
| Long-acting β-agonists | 172 (71) |
| Long-acting anticholinergics | 120 (50) |
| Methylxanthines | 34 (14) |
| Inhaled corticosteroid | 195 (81) |
| Long-term oral steroids | 6 (2) |
| Exacerbation characteristics | |
| Heart rate beats·min−1 | 102±20 |
| Respiratory rate breaths·min−1 | 24±5 |
| BP systolic/diastolic mmHg | 135±25/73±16 |
| Arterial blood gases | |
| Hydrogen mmHg | 41±8 |
| Pa,O2 kPa | 11±4 |
| Pa,CO2 kPa | 6±2 |
| Exacerbation (infection) type | |
| Anthonisen type 1# | 110 (45) |
| Anthonisen type 2# | 51 (21) |
| Anthonisen type 3# | 67 (28) |
| Leukocytosis¶ | 113 (47) |
| Raised C-reactive protein+ | 158 (74) |
| Haemoglobin g·dL−1 | 135±18 |
| Prescribed antibiotics | 164 (68) |
| Prescribed oral prednisolone | 217 (90) |
| Treated with NIV | 15 (6) |
| Length of stay days | 5 (3–8) |
| 12-month mortality§ | 21 (15) |
Data are presented as mean±sd, n (%) or median (interquartile range), unless otherwise stated. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; GOLD: Global Initiative for Chronic Obstructive Lung Disease; BP: blood pressure; Pa,O2: arterial oxygen tension; Pa,CO2: arterial carbon dioxide tension; NIV: noninvasive ventilation. #: according to the criteria of Anthonisen et al. [16]; ¶: white cell count >11×109 cells·L−1; +: >6 mg·dL−1; §: Royal Infirmary of Edinburgh (Edinburgh, UK).