Table 1.
Baseline demographic and clinical characteristics of the derivation and validation cohort, with and without exacerbations within 24 months from study entry
| Characteristics | Derivation cohort
|
Validation cohort
|
||
|---|---|---|---|---|
| Exacerbation (n=70) | No exacerbation (n=170) | Exacerbation (n=222) | No exacerbation (n=571) | |
| Mean age, years (±SD) | 73.6 (±5.2) | 73.3 (±5.0) | 67.9 (±10.0) | 67.2 (±9.7) |
| Male, n (%) | 51 (72.9) | 113 (66.5) | 119 (53.6) | 301 (52.7) |
| Current smokers, n (%) | 24 (34.3) | 34 (20.0) | 92 (41.4) | 202 (35.4) |
| Never smokers, n (%) | 5 (7.1) | 31 (18.2) | 15 (6.8) | 59 (10.3) |
| Pack years, median (IQR)a | 32.8 (18.4–54.0) | 23.3 (4.1–51.8) | 37.0 (23.0–47.0) | 30.0 (20.0–45.0) |
| Mean FEV1 %predicted (±SD)b | 64.2 (±20.5) | 74.0 (±20.0) | 65.6 (±18.1) | 72.5 (±16.7) |
| Inhaled corticosteroids, n (%) | 56 (80.0) | 102 (60.0) | 56 (25.2) | 123 (21.5) |
| Inhaled β2-mimetics, n (%) | 56 (80.0) | 111 (65.3) | 126 (56.8) | 233 (40.8) |
| Inhaled anti-cholinergics, n (%) | 45 (64.3) | 88 (51.8) | 122 (55.0) | 271 (47.5) |
| Previous exacerbations, n (%)c | 33 (47.1) | 23 (13.5) | 55 (24.8) | 39 (6.8) |
| Ischemic heart disease, n (%)d | 14 (20.0) | 38 (22.4) | 36 (16.2) | 101 (17.7) |
| Vascular disease, n (%)e | 10 (14.3) | 12 (7.1) | 41 (18.5) | 76 (13.3) |
Notes:
a
n=395: n=116 for exacerbation and n=279 for no exacerbation
b
n=782: n=218 for exacerbation and n=564 for no exacerbation
c
previous exacerbations = occurrence of an exacerbation in the year before study entry
d
ischemic heart disease = history of myocardial infarction, angina pectoris, percutaneous coronary intervention, or coronary artery bypass grafting
e
vascular disease = history of stroke, minor stroke, or peripheral arterial disease.
Abbreviations: FEV1, forced expiratory volume in 1 second; IQR, interquartile range; SD, standard deviation.