TABLE 4.
Variables associated with airflow obstruction in young adults
| Variable |
Univariate model
OR (95% CI) |
Multivariable models*
|
||
|---|---|---|---|---|
| Model 1, OR (95% CI) | Model 2, OR (95% CI) | Model 3, OR (95% CI) | ||
| Current smoking | 2.7 (1.9 to 3.8) | 2.6 (1.8 to 3.8) | 2.7 (1.9 to 4.0) | 2.7 (1.6 to 2.3) |
| Past smoking | 1.6 (1.1 to 2.4) | 1.6 (1.1 to 2.4) | 1.6 (1.0 to 2.4) | 1.7 (1.0 to 2.9) |
| Dust exposure | 1.4 (1.1 to 1.9) | NS | – | – |
| Respiratory infection before five years of age | 1.6 (1.0 to 2.4) | NS | – | – |
| Lung trouble before 16 years of age | 2.6 (1.9 to 3.7) | 1.6 (1.1 to 2.5) | 1.6 (1.0 to 2.4) | NS |
| Ever had asthma | 3.4 (2.5 to 4.7) | 1.8 (1.1 to 3.1) | 1.6 (0.9 to 2.9) | 1.8 (1.1 to 3.0) |
| Current asthma | 3.8 (2.6 to 5.7) | 1.9 (1.1 to 3.5) | 1.8 (1.0 to 3.3) | NS |
| Bronchial hyper-reactivity | 5.9 (4.1 to 8.6) | – | – | 5.3 (3.4 to 8.4) |
| Allergy | 1.9 (1.3 to 2.6) | – | 1.6 (1.2 to 2.2) | NS |
| Immunoglobulin E | 2.0 (1.3 to 2.9) | – | NS | – |
*
ORs were adjusted for all variables in the model in addition to sex and age. All significant univariate variables except bronchial hyper-reactiviy, allergy and immunoglobulin E were entered into model 1. In model 2, allergy and immunoglobulin E were added to significant variables in model 1. In model 3, bronchial hyper-reactivity was added to the significant variables in model 2. ‘–’ The variable was not fit into the model; NS Not significant