Table I.
Baseline demographic characteristics of the cohort by severity definition
| Characteristic | Age (y) |
Overall cohort (n = 478) |
||
|---|---|---|---|---|
| 2-4 (n = 85) |
5-11 (n = 235) |
12+ (n = 158) |
||
| Sex: male | 52 (61) | 151 (64) | 85 (54) | 288 (60) |
| Baseline lung function | ||||
| FEV1 (% predicted), median (IQR) | NA | 91 (78-102) | 92 (80-99) | NA |
| (n = 138) | (n = 122) | |||
| PEFR (% predicted), median (IQR) | NA | 87 (75-101) | 91 (85-100) | NA |
| (n = 58) | (n = 48) | |||
| Baseline asthma control score, median (IQR) | ||||
| TRACK | 55 (35-65) | NA | NA | NA |
| (c)ACT | NA | 19 (15-22) | 19 (16-22) | |
| ACQ | NA | 6 (2-12) | 6 (3-11) | |
| Previous influenza vaccination | 41 (48) | 186 (79) | 120 (76) | 332 (69) |
| Previous LAIV | 24 (28) | 134 (57) | 64 (41) | 222 (46) |
| Asthma severity | ||||
| “Persistent poor control”20: | ||||
| Age 2-4 y: ICS >200 μg + LTRA or ≥2 exacerbations in past year requiring oral steroids/hospitalization | 68 (80) | 88 (37) | 73 (46) | 229 (48) |
| Age 5-11 y: ICS ≥ 400 μg/d | ||||
| Age 12+y: ICS ≥ 800 μg/d | ||||
| High-dose ICSs, n (%) | ||||
| Age 2-4 y: ICS ≥ 400 μg/d | 48 (57) | 63 (27) | 97 (61) | 208 (44) |
| Age 5+ y: ICS ≥ 800 μg/d | ||||
| Severe asthma (according to ATS/ERS guidelines)22 | ||||
| High-dose ICS AND at least 1 of: | NA | 51 (22) | 71 (45) | 122 (31∗) |
| ACT score <20 | ||||
| ≥2 courses of systemic steroids in the past year | ||||
| Serious exacerbation (hospital admission in last year) | ||||
| FEV1 <80% | ||||
| “Difficult asthma”: persistence of symptoms despite treatment with high-dose therapies21 | 54 (64) | 46 (20) | 42 (27) | 142 (30) |
ATS, American Thoracic Society; ERS, European Respiratory Society; IQR, interquartile range; LTRA, leukotriene receptor antagonist; NA, not applicable/available; PEFR, peak expiratory flow rate.
Values are n (%) unless otherwise indicated.
∗
Excluding study participants <5 years.