Prevalence of COPD and outcome of logistic regression analysis in urban Liwang and rural Yunyan*
| COPD n (%) | Crude OR (95% CI) | p Value | Adjusted OR (95% CI) | p Value | |
|---|---|---|---|---|---|
| ETS, environmental tobacco smoke; BMI, body mass index; LPG, liquid petroleum gas. | |||||
| *Data of 3286 participants were analysed and are presented as number (%) of observations and OR (95% CI). | |||||
| †These variables were included in the multivariate logistic regression model. | |||||
| ‡Fuel type and local exhaust ventilation in kitchen excluded from multivariate model because they were collinear with urban/rural residence. | |||||
| Area† | 0.004 | 0.037 | |||
| Rural Yunyan | 176 (12.0) | 1.71 (1.26 to 2.33) | 1.83 (1.05 to 3.19) | ||
| Urban Liwang | 134 (7.4) | 1.00 (reference) | 1.00 (reference) | ||
| Sex† | <0.001 | <0.001 | |||
| Men | 218 (15.9) | 3.87 (3.04 to 4.92) | 2.90 (2.20 to 3.82) | ||
| Women | 92 (4.8) | 1.00 (reference) | 1.00 (reference) | ||
| Age group (years)† | <0.001 | <0.001 | |||
| 40–49 | 41 (3.6) | 1.00 (reference) | 1.00 (reference) | ||
| 50–59 | 45 (6.0) | 1.72 (1.15 to 2.55) | 1.57 (0.97 to 2.55) | ||
| 60–69 | 113 (13.0) | 3.97 (2.14 to 7.33) | 3.97 (2.04 to 7.74) | ||
| ⩾70 | 111 (20.7) | 7.53 (4.48 to 12.64) | 7.77 (4.25 to 14.21) | ||
| Education (years)† | 0.001 | 0.047 | |||
| 0 | 117 (11.2) | 1.78 (1.39 to 2.29) | 1.68 (1.01 to 2.81) | ||
| 1–6 | 112 (11.0) | 1.73 (1.17 to 2.55) | 1.09 (0.75 to 1.58) | ||
| ⩾7 | 81 (6.6) | 1.00 (reference) | 1.00 (reference) | ||
| Smoking status† | <0.001 | 0.029 | |||
| Non-smokers without ETS | 54 (6.0) | 1.00 (reference) | 1.00 (reference) | ||
| Non-smokers with ETS | 60 (5.0) | 0.82 (0.59 to 1.15) | 1.33 (0.85 to 2.08) | ||
| Smokers <15 pack-years | 37 (11.4) | 2.02 (1.06 to 3.85) | 1.40 (0.71 to 2.75) | ||
| Smokers ⩾15 pack-years | 159 (18.1) | 3.53 (2.51 to 4.97) | 1.83 (1.14 to 2.95) | ||
| Occupational exposure to dust† | 0.018 | 0.364 | |||
| Yes | 203 (11.0) | 1.51 (1.10 to 2.07) | 1.19 (0.78 to 1.82) | ||
| No | 107 (7.4) | 1.00 (reference) | 1.00 (reference) | ||
| Respiratory disease in family† | 0.002 | <0.001 | |||
| Yes | 99 (13.7) | 1.72 (1.30 to 2.28) | 1.98 (1.62 to 2.41) | ||
| No | 211 (8.2) | 1.00 (reference) | 1.00 (reference) | ||
| Cough in childhood† | 0.001 | <0.001 | |||
| Often/sometimes | 33 (18.6) | 2.30 (1.58 to 3.34) | 3.23 (2.17 to 4.82) | ||
| Seldom | 277 (8.9) | 1.00 (reference) | 1.00 (reference) | ||
| BMI (kg/m2)† | <0.001 | <0.001 | |||
| ⩾24.0 | 45 (4.3) | 0.39 (0.23 to 0.66) | 0.45 (0.26 to 0.79) | ||
| 18.5–23.9 | 212 (10.4) | 1.00 (reference) | 1.00 (reference) | ||
| <18.5 | 53 (24.2) | 2.76 (2.07 to 3.68) | 2.88 (1.97 to 4.23) | ||
| Life quality† | 0.123 | 0.330 | |||
| Poor | 43 (9.2) | 1.51 (0.92 to 2.48) | 0.79 (0.38 to 1.65) | ||
| General | 250 (9.8) | 1.60 (0.95 to 2.69) | 1.05 (0.60 to 1.85) | ||
| Good | 17 (6.1) | 1.00 (reference) | 1.00 (reference) | ||
| Fuel type‡ | 0.019 | 0.021 | |||
| LPG | 132 (7.3) | 1.00 (reference) | |||
| Coal | 21 (12.2) | 1.55 (0.74 to 3.22) | |||
| Biomass | 157 (12.0) | 1.72 (1.27 to 2.35) | |||
| Local exhaust ventilation in kitchen‡ | <0.001 | 0.011 | |||
| Yes | 111 (6.8) | 1.00 (reference) | |||
| No | 199 (11.9) | 1.85 (1.45 to 2.36) | |||