Results of multiple logistic regression analysis for respiratory symptoms
| Group | OR | 95% CI | p value (trend test) | |
|---|---|---|---|---|
| OR, odds ratio; CI, confidence interval. | ||||
| Odds ratios were adjusted for age, years of residence in the area, job status, smoking habit, type of heater used in home, and housing structure. | ||||
| Persistent cough | Group 3 | 1.00 | 0.788 | |
| Group 2 | 1.02 | 0.70 to 1.48 | ||
| Group 1 | 1.07 | 0.67 to 1.70 | ||
| Persistent phlegm | Group 3 | 1.00 | 0.001 | |
| Group 2 | 1.51 | 1.11 to 2.04 | ||
| Group 1 | 1.78 | 1.26 to 2.53 | ||
| Asthma | Group 3 | 1.00 | 0.052 | |
| Group 2 | 1.99 | 0.82 to 4.83 | ||
| Group 1 | 2.66 | 0.98 to 7.19 | ||
| Wheeze | Group 3 | 1.00 | 0.186 | |
| Group 2 | 1.39 | 0.95 to 2.01 | ||
| Group 1 | 1.34 | 0.85 to 2.11 | ||
| Breathlessness | Group 3 | 1.00 | 0.001 | |
| Group 2 | 0.84 | 0.47 to 1.50 | ||
| Group 1 | 2.70 | 1.48 to 4.91 | ||