Table 2.
Logistic regression model predicting presence of cough in the past 30 days
| Variable | Model 1A (n = 6,036) |
Model 1B (n = 5,926) |
Model 1C (n = 5,917) |
||||||
| OR | 95% CI | p value | OR | 95% CI | p value | OR | 95% CI | p value | |
| Smoking level (days smoking at least one puff) | |||||||||
| 0 | Ref | Ref | Ref | ||||||
| 5–10 | 1.54 | 1.19–1.99 | .001 | 1.40 | 1.06–1.84 | .02 | 1.32 | 1.00–1.74 | .05 |
| 11–20 | 1.49 | 1.08–2.06 | .01 | 1.39 | 0.99–1.95 | .06 | 1.27 | 0.89–1.79 | .18 |
| 21–30 | 1.68 | 1.37–2.06 | <.001 | 1.56 | 1.25–1.95 | <.001 | 1.31 | 1.00–1.71 | <.05 |
| Demographics | |||||||||
| Age | 0.86 | 0.83–0.90 | <.001 | 0.87 | 0.84–0.90 | <.001 | |||
| Gender (male vs. female) | 1.46 | 1.30–1.63 | <.001 | 1.45 | 1.29–1.62 | <.001 | |||
| Ethnicity (White vs. others) | 0.88 | 0.75–1.05 | .15 | 0.89 | 0.75–1.05 | .16 | |||
| Health variables (number of days) | |||||||||
| Drank alcohol | 1.03 | 1.02–1.04 | <.001 | 1.02 | 1.01–1.04 | <.001 | |||
| Exercising at least 20 min | 1.00 | 0.99–1.01 | .88 | 1.00 | 0.99–1.01 | .82 | |||
| Sleeping at least 6 hr | 0.99 | 0.98–1.00 | .006 | 0.99 | 0.98–1.00 | .007 | |||
| Environmental tobacco smoke (number of days exposed) | 1.01 | 1.00–1.02 | .02 | ||||||
Note. OR = odds ratio; CI = confidence interval.