Baseline characteristics at admission to hospital
| Anthropometrics, smoking and previous exacerbations | |
| Age (years) | 70 (9) |
| Male (%) | 58 (48.3) |
| BMI (kg/m2) | 25.3 (7.2) |
| Current smokers (%) | 47 (39.2) |
| Smoking history (pack years) | 40 (25–50) |
| Exacerbation frequency (/12 months) | 3 (1–5) |
| Hospital admission frequency (/12 months) | 1 (0–2) |
| Current exacerbation history | |
| Duration of symptoms (days) | 4 (2–7) |
| Systemic steroids prior to admission (%) | 26 (21.7) |
| Antibiotics prior to admission (%) | 30 (25.0) |
| Comorbidities | |
| Ischaemic heart disease (%) | 34 (28.3) |
| Cerebrovascular disease (%) | 13 (10.8) |
| Hypertension (%) | 53 (44.2) |
| Diabetes mellitus (%) | 20 (16.7) |
| Disease severity | |
| GOLD stage 2 (%)* | 4 (4) |
| GOLD stage 3 (%)* | 36 (36) |
| GOLD stage 4 (%)* | 60 (60) |
| MRC dyspnoea grade | 4 (4–5) |
| Admission investigations | |
| Arterial blood gases† | |
| pH | 7.39 (0.06) |
| paCO2 (kPa) | 5.82 (1.39) |
| paO2 (kPa) | 8.83 (2.98) |
| Bicarbonate (mEq/L) | 25.7 (3.8) |
| Base excess (mmol/L) | 0.63 (3.1) |
| Lactate (mmol/L) | 1.7 (1.5) |
| Routine laboratory tests | |
| C-reactive protein (mmol/L) | 65 (100) |
| Creatinine (μmol/L) | 72 (45) |
| Fibrinogen (mmol/L)‡ | 4.6 (1.5) |
| Leucocytes (×103/µL) | 11.9 (4.8) |
| Neutrophils (×103/µL) | 8.4 (5.0) |
| Eosinophils (×103/µL) | 0.3 (0.7) |
| Haemoglobin (g/dL) | 13.8 (1.7) |
| Platelets (×109/L) | 259 (87) |
| Radiographic consolidation | 25 (20.8) |
| Length of hospital stay (days) | 3 (2–6) |
| Deaths within 28 days (%) | 1 (0.8) |
| Readmission within 28 days (%) | 26 (21.7) |
| Deaths within 14 days (%) | 1 (0.8) |
| Readmission within 14 days (%) | 15 (12.5) |
Mean (SD), Median (IQR) or N (%).
*N=100.
†N=117.
‡N=68.
BMI, body mass index; GOLD, Global initiative for chronic Obstructive Lung Disease; MRC, Medical Research Council; PaCO2, arterial partial pressure of carbon dioxide; PaO2, arterial partial pressure of oxygen.