Characteristics of the patients studied at randomisation
| Characteristics | Placebo | Moxifloxacin |
| Subjects n | 20 | 20 |
| Age yrs | 69±10 | 69±7 |
| Males | 19 (95) | 19 (95) |
| Current smokers | 1 (5) | 1 (5) |
| Tobacco consumption pack-yrs | 43±21 | 49±24 |
| Chronic bronchitis | 19 (95) | 20 (100) |
| Cardiovascular comorbidity | 8 (40) | 6 (30) |
| More than two exacerbations in previous year | 6 (30) | 12 (60) |
| More than one hospitalisation in previous year | 4 (20) | 3 (15) |
| Post-bronchodilator FVC % pred | 78±24 | 70±18 |
| Post-bronchodilator FEV1 % pred | 53±16 | 47±15 |
| Treatment with inhaled corticosteroids | 16 (80) | 15 (75) |
| Sputum characteristics | ||
| Murray–Washington ≥3 | 14 (70%) | 14 (70%) |
| Haemophilus influenzae | ||
| Subjects | 11 (55) | 8 (40) |
| Load 106×CFU·mL−1 | 30 (0.5–60) | 30 (1–50) |
| Haemophilus parainfluenzae | ||
| Subjects | 6 (30) | 11 (55) |
| Load 106×CFU·mL−1 | 0.7 (0.4–188) | 0.6 (0.1–4.2) |
| Moraxella catarrhalis | 2 (10) | 2 (10) |
| Streptococcus pneumoniae | 1 (5) | 2 (10) |
| Enterobacteriaceae | 1 (5) | 0 |
| Polymicrobial | 1 (5) | 3 (15) |
Data presented as mean±sd, n (%) or median (interquartile range), unless otherwise stated. FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; CFU: colony forming units.