Relative strength of association with chronic bronchitis of genetic, lifestyle, clinical, and sociodemographic characteristics
| OR (95% CI) | p Value | |
| Smokingv not | 2.5 (1.8 to 3.4) | <0.001 |
| Inhalationv not | 1.7 (1.3 to 2.3) | <0.001 |
| Alcohol use, different categories referencing abstainers: | <0.001 | |
| Moderate use (1–21 drinks/week): | 0.8 (0.6 to 1.1) | |
| More than moderate (22–35 drinks/week): | 1.1 (0.7 to 1.6) | |
| Heavy use (>35 drinks/week): | 1.4 (0.95 to 2.1) | |
| Retiredv not | 1.4 (1.1 to 1.7) | 0.002 |
| Systolic blood pressure (mm Hg, risk associated with a one unit change) | 0.99 (0.98 to 0.997) | 0.002 |
| Height (cm, risk associated with a one unit change) | 0.98 (0.96 to 0.99) | 0.004 |
| NS-phenotype v others | 0.7 (0.6 to 0.99) | 0.038 |
Not in the final model (p>0.10): social class, weight, age.
Variables are ordered according to statistical strength of association with bronchitis after multivariate adjustment in a logistic regression model with backward elimination of variables.