TABLE 2.
Clinical characteristic of the four asthma k‐means clusters
| Asthma‐1 | Asthma‐2 | Asthma‐3 | Asthma‐4 | p‐value | |
|---|---|---|---|---|---|
| Number of subjects | 21 | 19 | 7 | 4 | |
| Female sex, N (%) | 9 (43) | 8 (42) | 2 (29) | 2 (50) | 0.89 b |
| Age (years) | 65.1 ± 9.2 | 58.7 ± 14.1 | 60.7 ± 11.3 | 53.3 ± 4.7 | 0.05 c |
| Age at asthma onset (year) | 47.0 ± 15.3 | 40.5 ± 14.3 | 39.3 ± 16.1 | 35.8 ± 16.3 | 0.09 c |
| Smoking index, pack‐years | 24.5 ± 24.2 | 29.0 ± 30.7 | 31.6 ± 27.3 | 16.6 ± 31.6 | 1.00 c |
| BMI (kg/m2) | 26.5 ± 5.2 | 23.3 ± 3.1 | 26.5 ± 11.0 | 23.7 ± 5.0 | 0.41 c |
| Aspirin sensitivity, N (%) | 4 (19) | 4 (21) | 0 (0) | 1 (25) | 0.61 b |
| Daily ICS dose (μg) | 1542 ± 412 | 1463 ± 146 | 1743 ± 600 | 1525 ± 50 | 0.60 c |
| Maintenance OCS use, N (%) | 10 (48) | 8 (42) | 1 (14) | 4 (100) | 0.16 b |
| AQLQ score | 5.4 ± 0.9 | 5.5 ± 0.8 | 6.0 ± 1.0 | 4.0 ± 1.3 | 0.35 c |
| Blood neutrophil count, cells/mm3 | 4860 (3744–6574) | 4533 (3489–5812) | 4788 (3944–5558) | 7143 (4371–10,089) | 0.53 d |
| Blood eosinophil count, cells/mm3 | 405 (57–763) | 435 (113–740) | 129 (83–433) | 450 (347–548) | 0.82 d |
| Serum total IgE, IU/ml | 177 (96–522) | 295 (157–394) | 179 (90–645) | 409 (279–482) | 0.93 d |
| Atopy, N (%) | 10 (48) | 8 (42) | 2 (29) | 1 (25) | 0.74 b |
| Sputum eosinophils, % | 12.2 (0.8–25.9) | 31.1 (9.4–43.4) | 0.8 (0.4–14.0) | 29.4 (23.4–37.1) | 0.08 d |
| FeNO, ppb | 28 (21–58) | 35 (18–55) | 19 (19–30) | 71 (57–112) | 0.12 d |
| FEV1, L a | 2.06 ± 0.66 | 2.36 ± 0.74 | 2.35 ± 0.66 | 2.21 ± 1.00 | 0.38 c |
| FEV1, % predicted a | 84.4 ± 13.8 | 88.3 ± 14.1 | 86.4 ± 12.5 | 82.7 ± 31.6 | 0.92 c |
| FEV1/FVC, % a | 63.3 ± 11.1 | 64.8 ± 14.4 | 63.8 ± 7.9 | 60.2 ± 14.2 | 0.80 c |
| DLco, % predicted | 105.5 ± 19.4 | 103.4 ± 21.2 | 93.6 ± 15.2 | 93.3 ± 26.1 | 0.13 c |
| Kco, % predicted | 115.0 ± 29.5 | 99.7 ± 15.3 | 92.46 ± 27.3 | 97.5 ± 30.9 | 0.03 c |
| %Low attenuation volume on chest CT | 0.49 (0.14–2.95) | 0.58 (0.20–3.46) | 0.78 (0.33–1.63) | 0.52 (0.42–6.07) | 0.82 d |
| Allergic rhinitis, N (%) | 7 (33) | 14 (74) | 3 (43) | 2 (50) | 0.07 b |
| Atopic dermatitis, N (%) | 3 (14) | 4 (21) | 1 (14) | 0 (0) | 0.94 b |
Note: Data are shown as mean ± SD, median (interquartile range), or number (%).
Abbreviations: AQLQ, the Asthma Quality of Life Questionnaire; BMI, body mass index; DLco, carbon monoxide diffusion capacity; FeNO, fractional exhaled nitric oxide; ICS, inhaled corticosteroid; Kco, carbon monoxide transfer coefficient; OCS, oral corticosteroid;
a
Maximum value of FEV1 among four procedures (see Section 2). FEV1/FVC was applied as the value corresponding to the maximum FEV1.
b
Fisher's exact test.
c
One‐way analysis of variance.
d
Kruskal–Wallis test.