Table 1. Baseline characteristics of the enrolled patients.
| A (n = 176) | B (n = 435) | C (n = 24) | D (n = 122) | Total (n = 757) | |
|---|---|---|---|---|---|
| Age (years) | 70.3±9.4 | 72.7±9.5 | 69.8±8.5 | 73.5±8.9 | 72.2±9.4 |
| <60 | 19 (10.8%) | 42 (9.7%) | 3 (12.5%) | 3 (2.5%) | 67 (8.9%) |
| 60–69 | 64 (36.4%) | 110 (25.3%) | 7 (29.2%) | 35 (28.7%) | 216 (28.5%) |
| 70–79 | 66 (37.5%) | 159 (36.6%) | 11 (45.8%) | 52 (42.6%) | 288 (38.0%) |
| ≧80 | 27 (15.3%) | 124(28.5%) | 3(12.5%) | 32 (26.2%) | 186 (24.6%) |
| Male gender | 168 (95.5%) | 422 (97.0%) | 24 (100%) | 114 (93.4%) | 728 (96.2%) |
| Smoking | |||||
| Never | 11 (6.3%) | 36 (8.3%) | 1 (4.2%) | 12 (9.8%) | 60 (7.9%) |
| Ex-smoker | 99 (56.3%) | 253 (58.2%) | 14 (58.3%) | 77 (63.1%) | 443 (58.5%) |
| Current smoker | 66 (37.5%) | 146 (33.6%) | 9 (37.5%) | 33 (27.0%) | 254 (33.6%) |
| BMI | 23.6±3.3 | 23.4±3.9 | 22.9±3.6 | 22.2±3.6 | 23.2±3.7 |
| Presence of wheezing | 53 (30.1%) | 183 (42.1%) | 14 (58.3%) | 89 (73.0%) | 339 (44.8%) |
| Spirometry (Post-bronchodilator test) | |||||
| FEV1/ FVC (%) | 57.6±9.0 | 55.0±9.5 | 54.9±9.6 | 50.7±10.0 | 54.9±9.7 |
| FEV1 (L) | 1.5±0.5 | 1.3±0.5 | 1.3±0.4 | 1.0±0.4 | 1.3±0.5 |
| FVC (L) | 2.6±0.8 | 2.3±0.7 | 2.3±0.6 | 2.0±0.6 | 2.3±0.7 |
| FEV1% predicted |
61.9±22.2 | 54.6±21.9 | 56.6±19.7 | 46.8±16.9 | 55.1±21.6 |
| GOLD spirometric classification | |||||
| I | 40 (22.7%) | 51 (11.7%) | 4 (16.7%) | 6 (4.9%) | 101 (13.3%) |
| II | 82 (46.6%) | 180 (41.4%) | 9 (37.5%) | 39 (32.0%) | 310 (41.0%) |
| III | 42 (23.9%) | 160 (36.8%) | 9 (37.5%) | 59 (48.4%) | 270 (35.7%) |
| IV | 12 (6.8%) | 44 (10.1%) | 2 (8.3%) | 18 (14.8%) | 76 (10%) |
| Positive bronchodilator test§ | 56 (31.8%) | 141 (32.4%) | 7 (29.2%) | 31 (25.4%) | 235 (31.0%) |
| CAT scores | 5.2±2.4 | 11.8±7.1 | 5.3±2.7 | 14.9±7.9 | 10.6±7.2 |
| ≧10 | 0 (0.0%) | 263 (60.5%) | 0 (0.0%) | 94 (77.0%) | 357 (47.2%) |
| mMRC | 0.8±0.4 | 2.2±0.7 | 0.9±0.3 | 2.5±0.9 | 1.9±0.9 |
| 2–4 | 0 (0.0%) | 370 (85.1%) | 0 (0.0%) | 107(87.7%) | 477 (63.0%) |
| Number of exacerbations in the previous year | 0.2±0.4 | 0.2±0.4 | 1.9±1.0 | 2.4±1.5 | 0.6±1.1 |
| 0–1 | 176 (100%) | 435 (100%) | 9 (37.5%) | 34 (27.9%) | 654 (86.4%) |
| ≧2 | 0 (0.0%) | 0 (0.0%) | 15 (62.5%) | 88 (72.1%) | 103 (13.6%) |
| Severe exacerbations | 0 (0.0%) | 0 (0.0%) | 15 (62.5%) | 82 (67.2%) | 97 (12.8%) |
| Inconsistency between the risk of exacerbations and level of airflow limitation | 54 (30.7%) | 204 (46.9%) | 13 (54.2%) | 45 (36.9%) | 316 (41.7%) |
| Inhaled pharmacological therapy | |||||
| None | 18 (10.2%) | 39 (9.0%) | 1 (4.2%) | 10 (8.2%) | 68 (9.0%) |
| LAMA alone | 42 (23.9%) | 129 (29.7%) | 9 (37.5%) | 21 (17.2%) | 201 (26.6%) |
| LABA alone | 12 (6.8%) | 17 (3.9%) | 1 (4.2%) | 4 (3.3%) | 34 (4.5%) |
| LABA + LAMA | 13 (7.4%) | 27 (6.2%) | 0 (0.0%) | 9 (7.4%) | 49 (6.5%) |
| LAMA + ICS | 1 (0.6%) | 13 (3.0%) | 0 (0.0%) | 2 (1.6%) | 16 (2.1%) |
| ICS/LABA | 43 (24.4%) | 97 (22.3%) | 2 (8.3%) | 38 (31.1%) | 180 (23.8%) |
| ICS/LABA + LAMA |
47 (26.7%) | 113 (26.0%) | 11 (45.8%) | 38 (31.1%) | 209 (27.6%) |
| Methylxanthines | 137(77.8%) | 317 (72.9%) | 15 (62.5%) | 94 (77.0%) | 563 (74.4%) |
| Co-morbidities | |||||
| Cardiovascular Disease# |
55 (31.3%) | 101 (23.2%) | 7 (29.2%) | 28 (23.0%) | 191 (25.2%) |
| Chronic lung disease※ |
23 (13.1%) | 31 (7.1%) | 3 (12.5%) | 8 (6.6%) | 65 (8.6%) |
| Lung cancer | 3 (1.7%) | 6 (1.4%) | 0 (0.0%) | 5 (4.1%) | 14 (1.8%) |
Abbreviations: BMI, body mass index; FEV1, forced expiratory volume in one second; FVC, forced vital capacity; GOLD, the Global initiative for Chronic Obstructive Lung Disease; CAT, COPD assessment test; mMRC, modified Medical Research Council dyspnea scale; LAMA, long-acting muscarinic antagonist; LABA, long-acting β2-agonist; ICS, inhaled corticosteroid.
§Positive bronchodilator test was defined as FEV 1 or FVC improvement from pre-dose value by ≥ 12% and ≥ 200 mL.
#Cardiovascular disease included ischemic heart disease, heart failure, atrial fibrillation and hypertension.
※Chronic lung disease included previous pulmonary tuberculosis, bronchiectasis and pneumoconiosis.