Patients n | 97 | 43 | | 77 | 54 | |
Basis of asthma definition | | | | | | |
Airway hyperresponsiveness, PC20 <8 mg·mL−1 | 0/97 (0%) | 6/43 (14%) | NA | NA | NA | NA |
Bronchodilator reversibility, FEV1 ≥12% | 66/97 (68%) | 19/43 (44.2%) | 0.028 | NA | NA | NA |
Persistent airflow limitation, FEV1 z-score <−1.96 | 5/96 (5.2%) | NA | NA | NA | NA | NA |
Spontaneous variability, FEV1 ≥12% | 1/97 (1%) | 19/43 (44.2%) | 0.994 | NA | NA | NA |
Diurnal peak flow variability, ≥15% | 8/97 (8.2%) | 2/43 (4.7%) | 0.452 | NA | NA | NA |
Basis of severe asthma definition | | | | | | |
High-dose ICS and trials of other controllers | 97/97 (100%) | NA | 1.000 | NA | NA | NA |
Persistent symptoms | 63/96 (65.6%) | NA | NA | NA | NA | NA |
Frequent exacerbations | 44/96 (45.8%) | NA | NA | NA | NA | NA |
Persistent airflow limitation | 5/96 (5.2%) | NA | NA | NA | NA | NA |
Maintenance oral corticosteroids | 19/96 (19.8%) | NA | NA | NA | NA | NA |
Symptom control | | | | | | |
Controlled | NA | 22/43 (51.2%) | NA | NA | 37/52 (71.2%) | NA |
Partially controlled | NA | 21/43 (48.8%) | NA | NA | 15/52 (28.8%) | NA |
Asthma history | | | | | | |
Age at diagnosis years | 3.25±0.27 (n=93) | 3.78±0.48 (n=41) | 0.305 | 1.74±0.12 (n=73) | 1.48±0.13 (n=46) | 0.146 |
ICU admission ever | 19/97 (19.6%) | 4/43 (9.3%) | 0.139 | 9/77 (11.7%) | 2/54 (3.7%) | 0.124 |
ICU admission in past year | 5/97 (5.2%) | 1/43 (2.3%) | 0.458 | 6/77 (7.8%) | 2/54 (3.7%) | 0.347 |
Intubation ever | 12/96 (12.5%) | 1/43 (2.3%) | 0.090 | 5/77 (6.5%) | 2/54 (3.7%) | 0.490 |
Reported triggers for respiratory symptoms | | | | | | |
Respiratory infections | 91/96 (94.8%) | 41/42 (97.6%) | 0.465 | 77/77 (100.0%) | 53/53 (100.0%) | 1.000 |
Pets | 62/92 (67.4%) | 29/38 (76.3%) | 0.315 | 14/60 (23.3%) | 11/49 (22.4%) | 0.913 |
Routine physical activities | 44/94 (46.8%) | 8/42 (19.0%) | 0.003 | 29/77 (37.7%) | 5/54 (9.3%) | <0.001 |
Physical exercise | 86/96 (89.6%) | 33/42 (78.6%) | 0.090 | 58/74 (78.4%) | 20/51 (39.2%) | <0.001 |
Aspirin | 3/53 (5.7%) | 1/22 (4.5%) | 0.845 | 1/51 (2.0%) | 0/41 (0.0%) | NA |
Cold air | 79/97 (81.4%) | 24/42 (57.1%) | 0.003 | 61/72 (84.7%) | 24/53 (45.3%) | <0.001 |
Pollutants | 55/85 (64.7%) | 17/37 (45.9%) | 0.055 | 18/55 (32.7%) | 5/47 (10.6%) | 0.011 |
Perfumes | 42/90 (46.7%) | 23/41 (56.1%) | 0.318 | 20/67 (29.9%) | 3/51 (5.9%) | 0.003 |
Wood smoke | 41/78 (52.6%) | 19/39 (48.7%) | 0.695 | 16/55 (29.1%) | 5/46 (10.9%) | 0.030 |
Dust | 75/93 (80.6%) | 28/42 (66.7%) | 0.080 | 35/70 (50.0%) | 13/50 (26%) | 0.009 |
Barns | 39/71 (54.9%) | 13/28 (46.4%) | 0.446 | 15/50 (30.0%) | 4/47 (8.5%) | 0.012 |
Stress | 55/92 (59.8%) | 18/43 (41.9%) | 0.053 | 24/63 (38.1%) | 5/51 (9.8%) | 0.001 |
Menstrual cycle | 7/87 (8.0%) | 3/40 (7.5%) | 0.916 | 0/72 (0.0%) | 0/48 (0.0%) | NA |
Pollen | 76/93 (81.7%) | 31/42 (73.8%) | 0.296 | 34/65 (52.3%) | 9/49 (18.4%) | <0.001 |
Fungus | 37/72 (51.4%) | 15/34 (44.1%) | 0.485 | 17/53 (32.1%) | 6/46 (13.0%) | 0.030 |
Early viral wheeze | 0/97 (0.0%) | 0/43 (0.0%) | NA | 5/77 (6.5%) | 18/54 (33.3%) | <0.001 |
Multi-trigger wheeze | 94/97 (96.9%) | 43/43 (100.0%) | 0.995 | 72/77 (93.5%) | 35/54 (64.8%) | <0.001 |
Asthma therapy | | | | | | |
Short-acting β-agonist | 95/97 (97.9%) | 42/43 (97.7%) | 0.921 | 75/77 (97.4%) | 40/54 (74.1%) | <0.001 |
Nebulised β-agonist | 22/97 (22.7%) | 2/43 (4.7%) | 0.019 | 16/77 (20.8%) | 2/54 (3.7%) | 0.013 |
ICS | | | | | | |
Any dose | 97/97 (100.0%) | 43/43 (100.0%) | 1.000 | 75/77 (97.4%) | 24/54 (44.4%) | <0.001 |
≤400 μg BUD equivalent | 0/96 (0.0%) | 42/43 (97.7%) | NA | 0/69 (0.0%) | 24/26 (92.3%) | NA |
≥800 μg BUD equivalent | 96/96 (100.0%) | 0/43 (0.0%) | NA | 69/69 (100.0%) | 2/26 (7.7%) | NA |
Oral corticosteroids | 23/97 (23.7%) | 0/43 (0.0%) | NA | 4/77 (5.2%) | 0/54 (0.0%) | NA |
Any LABA | 94/97 (96.9%) | 25/43 (58.1%) | <0.001 | 34/77 (44.2%) | 0/54 (0.0%) | NA |
Inhaled combination LABA/ICS | 89/97 (91.8%) | 25/43 (58.1%) | <0.001 | 32/77 (41.6%) | 0/54 (0.0%) | NA |
Anti-cholinergic | 14/97 (14.4%) | 2/43 (4.7%) | 0.112 | 7/77 (9.1%) | 3/54 (5.6%) | 0.457 |
Leukotriene modifier | 71/97 (73.2%) | 10/43 (23.3%) | <0.001 | 58/77 (75.3%) | 20/54 (37%) | <0.001 |
Xanthine | 15/97 (15.5%) | 0/43 (0.0%) | NA | 0/77 (0.0%) | 0/54 (0.0%) | NA |
Cromones | 10/97 (10.3%) | 1/43 (2.3%) | 0.140 | 1/77 (1.3%) | 0/54 (0.0%) | NA |
Antibiotic therapy | 17/97 (17.5%) | 1/43 (2.3%) | 0.036 | 10/77 (13.0%) | 5/54 (9.3%) | 0.511 |
Mucolytic | 2/97 (2.1%) | 0/43 (0.0%) | NA | 0/77 (0.0%) | 0/54 (0.0%) | NA |
Anti-IgE therapy | 17/97 (17.5%) | 0/43 (0.0%) | NA | 0/77 (0.0%) | 0/54 (0.0%) | NA |
SMART regime | 23/97 (23.7%) | 4/43 (9.3%) | 0.055 | 0/77 (0.0%) | 0/54 (0.0%) | NA |
Adherence to therapy, MARS total | 22.76±0.23 (n=94) | 21.3±0.48 (n=43) | 0.003 | 22.85±0.26 (n=73) | 22.18±0.43 (n=44) | 0.161 |