Table 1. Participant characteristics.
| All participants | Placebo | Azithromycin | p value | |
| N | 30 | 15 | 15 | |
| Clinical parameters | ||||
| Age, mean (SD); range | 70.8 (7.6) | 69.9 (8.9) | 71.7 (6.2) | 0.535 |
| Sex, Male/Female | 19/11 | 10/5 | 9/6 | 0.705 |
| Ex-smokers, n (%) | 22 (73.3%) | 11 (73.3) | 11 (73.3) | 1.0 |
| Pack years, mean (SD) | 46.11 (36.61) | 56.2 (43.2) | 36.0 (26.9) | 0.202 |
| FEV1% predicted, mean (SD) | 53.69 (13.74) | 51.1 (13.7) | 56.5 (13.7) | 0.297 |
| FEV1/FVC, mean (SD) | 57.79 (11.24) | 51.3 (11.3) | 52.3 (11.6) | 0.811 |
| Atopy, n (%) | 14 (46.67%) | 8 (53.3) | 6 (40.0) | 0.464 |
| ICS dose, BDP equivalent, µg/day, mean (range) | 1011, (400–2000) | 800 (500–1000), N = 15 | 1000 (800–2000), N = 11 | 0.196 |
| CCQ total score, mean (SD) | 16.0 (17.6) | 16.5 (6.97) | 15.4 (8.47) | 0.692 |
| SGRQ total score, mean (SD) | 34.2 (16.0) | 33.8 (15.7) | 34.5 (16.8) | 0.907 |
| mMRC dyspnea score, mean (SD) | 0.90 (0.80) | 0.87 (0.92) | 0.93 (0.70) | 0.825 |
| Inflammatory outcomes | ||||
| Total cell count, ×106/mL, median (q1,q3) | 5.54 (3.78,9.54) | 5.58 (3.78,9.54) | 4.68 (3.33,10.71) | 0.604 |
| Viability, %, median (q1,q3) | 88.0 (78.5,92.5) | 87.12 (73.9,92.86) | 88.4 (78.99,92.5) | 0.788 |
| Neutrophils, %, median (q1,q3) | 65.63 (46.5,71.25) | 68 (46.5,82.3) | 63.5 (42.75,71.0) | 0.547 |
| Neutrophils, ×104/mL, median (q1,q3) | 368.9 (209.3,556.9) | 380.4 (209.3,556.9) | 251.5 (165.4,570.7) | 0.468 |
| Eosinophils, %, median (q1,q3) | 2.03 (1.25,3.50) | 1.75 (1.25,3.0) | 3.25 (1.25,8.0) | 0.140 |
| Eosinophils, ×104/mL, median (q1,q3) | 10.85 (5.74,30.07) | 10.2 (4.3,18.5) | 16.1 (5.7,69.0) | 0.468 |
| Macrophages, %, median (q1,q3) | 31.63 (19.0,43.75) | 30.25 (15.1,46.5) | 32.5 (21.5,43.75) | 0.885 |
| Macrophages, ×104/mL, median (q1,q3) | 171.7 (117.0,248.0) | 209.3 (140.0,289.7) | 130.7 (88.7,205.7) | 0.152 |
| Lymphocytes, %, median (q1,q3) | 0.25 (0,1.25) | 0.25 (0,1.75) | 0.5 (0,0.75) | 0.470 |
| Lymphocytes, ×104/mL, median (q1,q3) | 2.57 (0,6.46) | 3.7 (0,9.0) | 1.2 (0,5.7) | 0.197 |
| Columnar epithelials, %, median (q1,q3) | 0.5 (0,1.75) | 0.5 (0,2.25) | 0.5 (0,1.25) | 0.525 |
| Columnar epithelials, ×104/mL, median (q1,q3) | 2.30 (0,5.36) | 2.5 (0,13.5) | 1.6 (0,5.0) | 0.460 |
| Squamous, %, median (q1,q3) | 16.33 (9.17,41.73) | 5.88 (0.74,11.31) | 3.14 (1.48,6.54) | 0.694 |
| CXCL8, ng/mL, median (q1,q3) | 16.22 (8.50,32.93) | 25.37 (10.32,58.88) | 11.93 (6.19,21.93) | 0.120 |
| NE, ng/mL, median (q1,q3) | 3038 (1318,6872) | 3868 (1722,10272) | 1950 (901.3,4756) | 0.141 |
| Bacteriology | N = 26 | N = 14 | N = 14 | |
| Bacterial load, ×107 cfu/mL, median (q1,q3) | 7.01 (1.84,14.5) | 6.55 (1.84,14.00) | 5.02 (1.65,20.0) | 0.783 |
| Bacterial pathogen isolated, n (%) | 9 (37%) | 3 (23%) | 6 (46%) | 0.205 |
| Computed tomography | ||||
| Quantitative scores | N = 14 | N = 7 | N = 7 | |
| Inspiratory lung density, mean (SD) | −856.82 (22.07) | −844.55 (23.14) | −869.08 (12.99) | 0.031 |
| % below −950 HU, inspiratory, mean (SD) | 14.53 (9.86) | 11.96 (9.66) | 17.09 (10.10) | 0.351 |
| % below −856 HU, inspiratory, mean (SD) | 64.73 (8.90) | 58.95 (8.81) | 70.52 (3.97) | 0.008 |
| Expiratory/Inspiratory mean lung density, mean (SD) | 0.92 (0.04) | 0.92 (0.05) | 0.93 (0.03) | 0.536 |
| Inspiratory PI, mm, mean (SD) | 3.82 (0.07) | 3.84 (0.10) | 3.80 (0.05) | 0.459 |
| Expiratory PI, mm, mean (SD) | 3.94 (0.12) | 3.94 (0.17) | 3.95 (0.09) | 0.902 |
| Qualitative scores | N = 17 | N = 9 | N = 6 | |
| Extent of bronchiectasis score, median (q1,q3) | 1.0 (0.0,5.5) | 5 (1.0,8.0) | 0.5 (0.0,2.0) | 0.160 |
| Severity of bronchiectasis score, median (q1,q3) | 1.0 (0.0,3.5) | 3.0 (1.0,5.0) | 0.5 (0.0,2.0) | 0.160 |
| Bronchial wall thickness score, median (q1,q3) | 3.0 (2.0,4.5) | 3 (3,5) | 2 (0,4) | 0.204 |
| Bronchial wall thickness >2, n (%) | 2.0 (12.0%) | 2 (20%) | 0 (0%) | 0.331 |
| Total lung score, median (q1,q3) | 5.5 (4.0,12.0) | 9 (4,16) | 5 (0,6) | 0.102 |
| Total emphysema score, median (q1,q3) | 0.0 (0.0,20.0) | 2.1 (0.0,23.3) | 0.0 (0.0,20.0) | 0.673 |
| Number of lobes decreased attenuation >0, median (q1,q3) | 5.0 (3.0,6.0) | 5 (4,6) | 3 (2,5) | 0.088 |
| Mucus plugging (large or small airways), n (%) | 2.0 (12.0%) | 2 (20%) | 0 (0%) | 0.331 |
| Consolidation present in any lobe, n (%) | 5.0 (29.4%) | 2 (20%) | 3 (43%) | 0.314 |
BDP equivalent: dose of inhaled corticosteroids is calculated as beclomethasone equivalents where 1 µg of beclomethasone = 1 µg budesonide = 0.5 µg fluticasone; CCQ: Clinical COPD Questionnaire; SGRQ: St George Respiratory Questionnaire; mMRC: modified Medical Research Council; cfu: colony-forming units; PI: Internal perimeter.