Table 4.
Association between SES (educational level) and respiratory health indicators and its alteration by respiratory health risk factors Stepwise logistic regression analysis
|
Frequent cough1 N = 944 |
Frequent cough with phlegm production1 N = 938 |
Bronchial asthma N = 1203 |
COPD FEV1/FVC <0.7 N = 1172 |
FEV1 <80% N = 1216 |
FVC <80% N = 1216 |
||
| Model I SES (educational level) unadjusted, 3 categories as continuous variables | OR | 2.01 | 2.02 | 2.33 | 2.46 | 1.83 | 1.99 |
| 95%CI | (1.31–3.10) | (1.15–3.56) | (0.96–5.65) | (1.04–5.78) | (1.22–2.74) | (1.38–2.88) | |
| p-value | 0.001 | 0.015 | 0.061 | 0.040 | 0.003 | <0.001 | |
| Model II SES adjusted for occupational exposure2 | OR | 1.95 | 1.97 | 2.28 | 2.40 | 1.78 | 1.95 |
| 95%CI | (1.26–3.00) | (1.11–3.48) | (0.94–5.56) | (1.01–5.68) | (1.18–2.68) | (1.35–2.83) | |
| p-value | 0.003 | 0.020 | 0.068 | 0.046 | 0.005 | <0.001 | |
| %-change | 6% | 5% | 4% | 4% | 6% | 4% | |
| Model III SES additionally adjusted for current smoking | OR | 1.91 | 1.95 | 2.18 | 2.26 | 1.71 | 1.92 |
| 95%CI | (1.23–2.97) | (1.10–3.46) | (0.89–5.32) | (0.94–5.41) | (1.13–2.58) | (1.32–2.79) | |
| p-value | 0.004 | 0.023 | 0.088 | 0.068 | 0.011 | 0.001 | |
| %-change | 10% | 7% | 11% | 14% | 14% | 7% | |
| Model IV SES additionally adjusted for 5-year mean PM10 | OR | 1.92 | 1.92 | 2.27 | 2.20 | 1.59 | 1.79 |
| 95%CI | (1.23–2.99) | (1.07–3.41) | (0.92–5.59) | (0.91–5.32) | (1.05–2.42) | (1.23–2.61) | |
| P-value | 0.004 | 0.028 | 0.074 | 0.080 | 0.029 | 0.002 | |
| %-change | 9% | 10% | 5% | 18% | 29% | 20% | |
| Model V SES additionally adjusted for distance to major road with >10.000 cars/day = 100 m | OR | not applicable | not applicable | 2.28 | 2.12 | 1.56 | 1.78 |
| 95%CI | (0.92–5.62) | (0.88–5.10) | (1.03–2.37) | (1.22–2.60) | |||
| P-value | 0.074 | 0.095 | 0.037 | 0.003 | |||
| %-change | 4% | 23% | 33% | 21% |
1 Only women living in a distance more than 100 m to the nearest major road with heavy traffic
2 Dust, gases, vapours, wet conditions or extreme temperature
Abbreviations:
OR: Odds ratio for <10 years education versus >10 years education; 95%CI: 95% Confidence interval; PM10: Particulate matter with aerodynamic diameter of ≤ 10 μm, calculated as PM10 = 0.71*TSP; TSP: Total suspended particles; FEV1: Forced expiratory volume in 1 second; FVC: Forced vital capacity; COPD: Chronic obstructive pulmonary disease; %-change: Calculated as the percentage reduction in the 'excess odds' due to adjustment for that factor