Table 4 Adjusted odds ratio and 95% CI of SES on COPD prevalence according to smoking status*
| Â | Â | Never smoker | Â | Smoker |
|---|---|---|---|---|
| Â | COPD (%) | Adjusted OR(95%CI) | COPD (%) | Adjusted OR(95%CI) |
Educational level | Â | Â | Â | Â |
   ≥ 12 years | 101 (1.3) | 1 | 80 (2.2) | 1 |
   9-11 years | 142 (1.4) | 1.06 (0.81-1.37) | 191 (3.1) | 1.36 (1.04-1.78) |
   < 9 years | 509 (3.5) | 1.77 (1.40-2.25) | 392 (5.8) | 1.64 (1.26-2.12) |
   P for trend |  | < 0.001 |  | < 0.001 |
Household Income | Â | Â | Â | Â |
   High | 162 (1.8) | 1 | 132 (3.2) | 1 |
   Middle | 213 (2.0) | 1.08 (0.87-1.34) | 186 (3.3) | 0.88 (0.69-1.11) |
   Low | 305 (3.3) | 1.31 (1.05-1.62) | 284 (5.6) | 1.17 (0.93-1.48) |
   P for trend |  | 0.011 |  | 0.071 |