Table 1.
Baseline characteristics of the study subjects (n = 132).
| Total (n = 132) | Exacerbation (n = 52) | Non-exacerbation (n = 80) | P | |
|---|---|---|---|---|
| Female (%) | 82 (62) | 33 (63) | 49 (61) | 0.855 |
| Age (year) | 62.5 (55.0–72.0) | 60.5 (56.4–63.4) | 63.5 (59.5–65.5) | 0.166 |
| Duration of asthma diagnosis (year) | 5.0 (2.0–12.0) | 7.0 (3.0–16.0) | 5.0 (2.0–12.3) | 0.293 |
| Smoking hx (%) | 39 (29) | 16 (31) | 23 (29) | 0.847 |
| Current smoker (%) | 5 (4) | 1 (2) | 4 (5) | 0.648 |
| Body mass index (kg/m2) | 24.6 (22.0–27.7) | 24.6 (22.2–26.9) | 24.4 (21.3–26.7) | 0.310 |
| Family history of asthma (%) | 48 (36) | 21 (40) | 27 (34) | 0.464 |
| Atopy (%) | 72 (55) | 24 (46) | 48 (60) | 0.153 |
| Comorbidity | ||||
| Allergic rhinitis (%) | 95 (72) | 35 (67) | 60 (75) | 0.428 |
| Hypertension (%) | 60 (45) | 24 (46) | 36 (45) | 1.000 |
| Diabetes mellitus (%) | 27 (20) | 9 (17) | 18 (23) | 0.515 |
| GERD (%) | 23 (17) | 9 (17) | 14 (18) | 1.000 |
| Heart failure (%) | 12 (9) | 5 (10) | 7 (9) | 1.000 |
| Bronchiectasis (%) | 6 (5) | 3 (6) | 3 (4) | 0.680 |
| Nasal polyp (%) | 4 (3) | 2 (4) | 2 (3) | 0.646 |
| Pulmonary function test | ||||
| FEV1/FVC (%) | 66.9 (56.8–76.8) | 66.4 (59.2–74.8) | 66.6 (54.8–76.9) | 0.845 |
| FEV1 (liter) | 1.45 (0.96–2.05) | 1.54 (0.96–2.06) | 1.40 (0.99–2.09) | 0.970 |
| FEV1%pred (%) | 65.3 (50.3–80.7) | 68.0 (46.3–80.6) | 63.0 (50.4–80.3) | 0.543 |
| FVC (liter) | 2.14 (1.59–2.91) | 2.20 (1.59–2.94) | 2.17 (1.61–2.96) | 0.944 |
| FVC %pred (%) | 79.6 (66.4–94.8) | 78.0 (61.0–95.0) | 80.1 (69.4–106.9) | 0.495 |
| Positive BDR (%) | 20 (15) | 7 (13) | 13 (16) | 0.805 |
| %Reversibility of FEV1 | 5.0 (1.0–9.9) | 4.5 (0.2–8.4) | 5.0 (1.0–11.2) | 0.228 |
| Fixed airflow limitation (%) | 68 (52) | 27 (52) | 41 (51) | 1.000 |
| Use of ICS and | ||||
| LABA (%) | 91 (69) | 33 (63) | 58 (73) | 0.336 |
| LABA and LAMA (%) | 31 (23) | 11 (21) | 20 (25) | 0.678 |
| Leukotriene modifier (%) | 56 (42) | 19 (37) | 37 (46) | 0.286 |
| Theophylline (%) | 80 (61) | 29 (56) | 51 (64) | 0.369 |
| Anti-histamine (%) | 8 (6) | 2 (4) | 6 (8) | 0.479 |
| Maintenance oral prednisolone (%) | 9 (7) | 2 (4) | 7 (9) | 0.482 |
| Omalizumab (%) | 10 (8) | 4 (8) | 6 (8) | 1.000 |
| ACT | 21 (19–23) | 20.0 (18.7–23.0) | 21.0 (18.7–23.0) | 0.157 |
| Uncontrolled asthma (%) | 92 (70) | 39 (74) | 53 (66) | 0.335 |
| Asthma exacerbation in the year prior to the study (%) | 73 (55) | 40 (77) | 33 (41) | < 0.001 |
| Severe exacerbation (/year) | 0.57 ± 0.74 | 0.77 ± 0.75 | 0.44 ± 0.70 | 0.003 |
| Serious exacerbation (/year) | 0.18 ± 0.57 | 0.27 ± 0.66 | 0.13 ± 0.51 | 0.079 |
| Asthma exacerbation during 1-year follow-up | ||||
| Severe exacerbation (/year) | 0.45 ± 0.98 | 1.13 ± 1.29 | 0 | |
| Serious exacerbation (/year) | 0.29 ± 1.01 | 0.71 ± 1.52 | 0 | |
Data were reported as mean ± standard deviation, median (interquartile range) or number (%).
ACT asthma control test, BDR bronchodilator reversibility, FEV1 forced expiratory volume in one second, FVC forced vital capacity, GERD gastroesophageal reflux disease, ICS inhaled corticosteroid, LABA long-acting beta 2 agonist, LAMA long-acting muscarinic antagonist.