Table 4.
Comparison of baseline characteristics of the TRAIL cohort, between those still alive and those who died of asthma-related causes
| Alive (n = 978) | Dead (n = 93) | p-value | |
|---|---|---|---|
| Sex, n women (%) | 599 (61) | 50 (54) | 0.18 |
| Age, yrs | 36 (15) | 56 (12) | < 0.001 |
| Decade of inclusion | |||
| 1974–1979 | 144 (15) | 20 (22) | 0.093 |
| 1980–1989 | 731 (75) | 68 (73) | |
| 1990 | 103 (10) | 5 (5) | |
| Years since symptom debut | 4 (2–13) | 10 (3–25) | < 0.001 |
| Ever smokera, n (%) | 331 (33.8) | 48 (52) | < 0.001 |
| Pack-yearsb | 7.7 (3.5–14) | 15 (7.5–22.3) | < 0.001 |
| History of asthma exacerbation, n (%) | 159 (16) | 14 (15) | 0.883 |
| Daily symptoms, n (%) | 340 (35) | 58 (62) | < 0.001 |
| Daily β2-agonist usage | 2 (2–4) | 4 (3–6) | < 0.001 |
| ICS dosage at baseline | 200 (0–400) | 400 (0–600) | 0.082 |
| Lung function | |||
| FEV1% pred | 85 (17.6) | 62 (21.5) | 0.006 |
| FVC % pred | 94 (15) | 80 (19) | < 0.001 |
| FEV1/FVC ratio | 75 (11) | 61 (13) | 0.024 |
| BD Reversibility, % | 18 (16–26) | 28 (16–43) | < 0.001 |
| AHR | 2.35 (1.60–4.36) | 2.00 (1.10–3.98) | 0.280 |
| Peak flow variability, % | 22 (15–29) | 23 (13–26) | 0.725 |
| Blood Eosinophils, × 109/l | 0.34 (0.21–0.57) | 0.42 (0.21–0.57) | 0.521 |
| Total IgE, IU/l | 125 (41–342) | 105 (36–316) | 0.317 |
| Negative skin prick test, n (%) | 403 (41) | 66 (71) | < 0.001 |
Data are presented as mean (standard deviation) or median interquartile range), unless otherwise stated
AHR airway hyperresponsiveness, BD bronchodilator, FEV1 forced expiratory volume in 1 Second, FVC forced vital capacity, ICS inhaled corticosteroids, IU International Units
aCurrent or ex-smokers
bFor ever smokers