Table 1.
Characteristics of the subjects included in the analyses.
| SAGE (n=1,002) | GALA II (n=2,181) | |||
|---|---|---|---|---|
| Exacerbators (n=470) | Non-exacerbators (n=532) | Exacerbators (n=1,283) | Non-exacerbators (n=898) | |
| Gender (% female) | 229 (48.7) | 286 (50.4) | 582 (45.4) | 403 (44.9) |
| Mean age in years ± SD | 14.3±5.6a | 14.7±4.1 | 12.2±3.1a | 13.4±3.5 |
| African ancestry (%) | 79.4±10.7 | 78.4±12.1 | 18.9±13.2a | 12.6±11.9 |
| Native American ancestry (%) | NA | NA | 22.9±22.6b | 37.4±25.5 |
| Asthma control, n (%) | ||||
| Well controlled | 60 (15.7) | 182 (36.8) | 210 (16.4)a | 431 (48.0) |
| Partially controlled | 112 (29.4) | 150 (30.4) | 533 (41.5)a | 282 (31.4) |
| Poorly controlled | 209 (54.9) | 162 (32.8) | 540 (42.1)a | 185 (20.6) |
| Treatment category, n (%) | ||||
| Step 1 | 111 (23.6) | 249 (47.1) | 210 (16.4)a | 431 (48.0) |
| Step 2 | 183 (39.0) | 210 (39.7) | 533 (41.5)a | 282 (31.4) |
| Step 3 | 176 (37.4) | 70 (13.2) | 540 (42.1)a | 185 (20.6) |
| Baseline lung function | ||||
| FEV1 (%) predicted | 91.2±11.9 | 92.4±11.6 | 97.9±15.7a | 103.6±14.4 |
| FVC (%) predicted | 96.5±11.8 | 97.0±10.9 | 102.0±16.0a | 107.3±15.3 |
| FEV1/FVC (%) predicted | 94.3±8.3 | 95.3±7.6 | 96.4±7.6a | 97.2±7.2 |
| Total serum IgE (IU/ml) | 168.3±4.9a | 139.7±4.6 | 254.0±4.5a | 147.4±4.7 |
Abbreviations: FEV1, forced expiratory volume in one second; FVC, forced vital capacity; NA: Not available/applicable.
For continuous variables, the mean and standard deviation are displayed. For total serum IgE levels, the geometrical mean and standard deviation are reported. For categorical variables, the number and percentage of subjects in each category are shown.
p< 0.01 for the comparison between asthma cases with exacerbations and controls.
The severity medication regime was categorized into three levels based on the use of short beta agonists (step 1), one inhaled corticosteroid, leukotriene inhibitor, or theophylline tablet (step 2), more than one or a combination of an inhaled corticosteroid, leukotriene inhibitor, or theophylline tablet or a combination of inhaled corticosteroids and long-beta agonists (step 3).
Asthma control and treatment category were available for 875 and 999 individuals from SAGE, respectively. Asthma control and severity were available for 2,181 and 2,170 individuals from GALA II, respectively. FEV1 was available for 807 and 2,068 SAGE and GALA II subjects. FVC was available for 821 participants from SAGE and 2,077 subjects from GALA II. FEV1/FVC was available for 804 and 2,068 SAGE and GALA II subjects. Total serum IgE levels were available for 784 and 1,856 SAGE and GALA II subjects.