| Characteristic | Ciprofloxacin DPI | Placebo |
| Subjects n | 60 | 64 |
| Age years | 64.7±11.8 | 61.4±11.9 |
| Sex | ||
| Male | 21 (35.0) | 21 (32.8) |
| Female | 39 (65.0) | 43 (67.2) |
| Ethnicity | ||
| Caucasian | 60 (100.0) | 63 (98.4) |
| Asian | 0 | 1 (1.6) |
| Weight kg | 70.2±16.4 | 69.1±17.2 |
| BMI kg·m−2 | 25.6±5.5 | 25.1±5.6 |
| FEV1 % pred | 57.2±13.7 | 54.6±14.8 |
| Subjects with exacerbations in previous 12 months | ||
| 1–2 exacerbations | 30 (50.0) | 35 (54.7) |
| 3–4 exacerbations | 25 (41.7) | 26 (40.6) |
| ≥5 exacerbations | 5 (8.3) | 3 (4.7) |
| Baseline total bacterial load log10 CFU·g−1 | 7.19±1.94 | 6.92±1.90 |
| Baseline bacterial isolates in ≥5% subjects# | ||
| Pseudomonas aeruginosa | 32 (53.3) | 35 (54.7) |
| Haemophilus influenzae | 14 (23.3) | 16 (25.0) |
| Staphylococcus aureus | 8 (13.3) | 17 (26.6) |
| Streptococcus pneumoniae | 7 (11.7) | 2 (3.1) |
| Moraxella catarrhalis | 5 (8.3) | 3 (4.7) |
| Klebsiella pneumoniae | 5 (8.3) | 0 |
| Proteus mirabilis | 3 (5.0) | 4 (6.3) |
| Klebsiella oxytoca | 3 (5.0) | 2 (3.1) |
Data are presented as mean±sd or n (%), unless otherwise stated. DPI: dry powder for inhalation; BMI: body mass index; FEV1: forced expiratory volume in 1 s; % pred: % predicted. #: no significant differences between ciprofloxacin DPI and placebo for isolates were reported apart from for K. pneumoniae (p=0.024).