Table 3.
Association of the sum of the risk factors (categorized as 0–1, 2–3, and 4–5 risk factors) with severe adult-onset asthma by using a question-based definition of severe asthma (Sev-Q)
| N1 total (n with severe asthma) | OR1 (95% CI) | p1 | N2 total (n with severe asthma) | OR2 (95% CI) | p2 | |
|---|---|---|---|---|---|---|
| 0–1 | 215 (3) | 1 | 215 (3) | 1 | ||
| 2–3 | 831 (47) | 4.24 (1.31–13.75) | .016 | 829 (45) | 4.06 (1.25–13.18) | .020 |
| 4–5 | 269 (44) | 13.82 (4.23–45.18) | < .001 | 262 (37) | 11.62 (3.53–38.25) | < .001 |
Bold values denote statistical significance at the p < 0.05 level
Risk factors were male sex, ≥ 2 siblings, ever smoking, NERD, and ≥ 1 other disease. When counting the total sum of the five risk factors, 27 (2.0%), 188 (13.9%), 433 (32.1%), 398 (29.5%), 260 (19.3%) and 9 (0.7%) had 0, 1, 2, 3, 4, and 5 risk factors, respectively. The risk for severe asthma (Sev-Q) significantly and gradually increased with the sum of the five risk factors (OR (95% CI) = 2.30 [1.81–2.93] for each additional unit, p < 0.001). NERD = patient-reported NSAID-exacerbated respiratory disease. OR = odds ratio. CI = confidence interval. Severe asthma (Sev-Q) was defined as self-reported severe asthma and asthma symptoms causing much harm and regular impairment and ≥ 1 oral corticosteroid course/year or regular oral corticosteroids and/or waking up in the night due to asthma symptoms/wheezing ≥ a few times/month. 1Complete patients in whom the variable data were available. 2More stringent definition of severe asthma by including only those subjects with regular use of inhaled corticosteroid (Sev-Q + ICS)