Table 2. Odds of increased respiratory impairment given various subject characteristics (race, atopic status and inhaled steroid use [n (%)]; age and lung function [mean (SD)]).
| IC 0/1n = 24 | IC 2/3n = 16 | OR* | 95% CI | |
| Race, Caucasian | 15 (63) | 11 (69) | 1.32 | 0.35, 5.05 |
| Atopy, positive | 6 (32) | 7 (53.8) | 2.53 | 0.59, 10.86 |
| Age (years) | 61.8 (11.5) | 61.3 (7.7) | 1.00 | 0.94, 1.10 |
| Inhaled steroid use | 7 (29.2) | 9 (56.3) | 3.12 | 0.83, 11.72 |
| FEV1 percent predicted | 91.6 (12. 6) | 70.5 (12.0) | 0.82** | 0.71, 0.94 |
| PC20-FEV1 (methacholine, mg/ml) | 9.1 (6.9) | 3.4 (5.1) | 0.86** | 0.76, 0.97 |
| Change of FEV1 (L) | −1.2 (0.5) | −1.8 (0.5) | 0.06** | 0.01, 0.49 |
| Change of PC20-FEV1 (mg/ml) | 4.0 (8.0) | −1.6 (9.1) | 0.90 | 0.81, 1.02 |
| Years from initial diagnosis | 25.8 (6.4) | 22. 6 (7.2) | 0.87 | 0.76, 1.01 |
| Years from last exposure | 17.1 (8.3) | 16.8 (10.9) | 1.00 | 0.93, 1.07 |
| Change of FEV1 per year (L) | −.06 (.05) | −0.08 (0.04) | 0.005** | 0.00, 0.55 |
Italics depicts the 3 components of the impairment score.
*
Odds of being in IC 2/3 versus IC 0/1 with given characteristic, from logistic regression model with, in each analysis, adjustment for age (except for fevpp, where age is already incorporated, and for race, atopy, inhaled steroids) and years since last exposure (except for race, atopy, inhaled steroids).
**
p<0.05