Table 3.
Differences in asthma-related health by subspecialty
| Subspecialty |
|||
|---|---|---|---|
| Pulmonary (n=935) | Allergy (n=2,407) | p value | |
| Age at diagnosis, mean ± SD | 25.9 ± 20.2 | 24.7 ± 18.8 | 0.12 |
| Physician-assessed severity | <0.001 | ||
| Mild | 34 (4%) | 53 (2%) | |
| Moderate | 365 (39%) | 1,159 (49%) | |
| Severe | 530 (57%) | 1,177 (49%) | |
| Classified as `difficult-to-treat' by physician* | 885 (95%) | 2,268 (95%) | 0.70 |
| GINA classification | <0.001 | ||
| Mild | 21 (2%) | 62 (3%) | |
| Moderate | 274 (31%) | 1,003 (43%) | |
| Severity | 603 (67%) | 1,265 (54%) | |
| FEV1 percent predicted, mean ± SD | 71 ± 25% | 75 ± 23% | <0.001 |
| FEV1 percent predicted, n (%) | <0.001 | ||
| ≥80% | 309 (36%) | 915 (41%) | |
| >60% to <80% | 237 (28%) | 747 (34%) | |
| ≤60% | 305 (36%) | 560 (25%) | |
| Persistent airflow obstruction† | 176 (68%) | 422 (57%) | 0.002 |
| ATAQ control index | <0.001 | ||
| 0 problems | 116 (13%) | 421 (18%) | |
| 1 problem | 161 (18%) | 482 (21%) | |
| 2 problems | 265 (29%) | 756 (32%) | |
| 3+ problems | 364 (40%) | 697 (30%) | |
| Serum IgE level, IU/ml | |||
| Geometric cean (95% confidence level) | 74 (67–83) | 88 (82–94) | 0.009 |
| Median | 75 | 96 | |
| Range | 1–9,212 | 1–15,101 | |
| Self-reported asthma triggers | |||
| Pollen | 618 (67%) | 1,675 (70%) | 0.06 |
| Pets or animals | 427 (46%) | 1,311 (55%) | <0.001 |
| Moldy, musty, or damp places | 553 (60%) | 1,512 (63%) | 0.06 |
| Dust | 721 (78%) | 1,893 (79%) | 0.40 |
| Cold air | 659 (71%) | 1,782 (75%) | 0.05 |
| Change in weather | 708 (77%) | 1,704 (71%) | 0.003 |
| Tobacco smoke | 701 (76%) | 1,766 (74%) | 0.28 |
| Indoor irritants (e.g., carpets, stove, pillows) | 376 (41%) | 953 (40%) | 0.70 |
| Emotional stress | 581 (63%) | 1,478 (62%) | 0.63 |
| Exercise | 729 (79%) | 1,920 (80%) | 0.30 |
| Aspirin | 127 (14%) | 325 (14%) | 0.93 |
| Co-morbid conditions | |||
| Allergic rhinitis | 520 (56%) | 1,855 (78%) | <0.001 |
| Atopic dermatitis | 120 (13%) | 331 (14%) | 0.59 |
| Emphysema or COPD | 136 (15%) | 149 (6%) | <0.001 |
| History of pneumonia | 606 (65%) | 1,384 (58%) | <0.001 |
| GERD | 98 (11%) | 284 (12%) | 0.28 |
Reported p values based on t test for continuous variables, Chi-square test for categorical variables, and Chi-square test for trend (Mantel-Haenszel) for ordinal variables.
*
`Difficult-to-treat' defined as difficulty adhering to the regimen, requirement for multiple drugs, inability to avoid triggers, frequent or severe exacerbations, or unresponsiveness to therapy. Subjects classified as difficult-to-treat could be categorized as either mild, moderate, or severe.
†
`Persistent airflow obstruction' defined as post-bronchodilator FEV1/FVC ratio of ≤70% on at least two visits 12 months apart.