|
Exposure variables
|
Prevalence of COPD among participants,% (n/N)
|
OR (95%CI)
|
|---|
|
Smoking exposure
|
Annual mean PM2.5 exposure
|
Model 1a
|
Model 2b
|
|---|
|
Non-smokers
|
N/A
|
6.4 (132/2073)
|
1
| |
1
| |
|
Smokers
|
N/A
|
20.6 (275/1334)
|
2.64 (1.89, 3.68)
| |
2.46 (1.76, 3.43)
| |
|
N/A
|
< 75 μg/m3
|
10.9 (/2,462,267)
|
1
| |
1
| |
|
N/A
|
≥ 75 μg/m3
|
14.1 (161/1140)
|
1.26 (1.01, 1.58)
| |
1.29 (1.02, 1.64)
| |
|
Non-smokers
|
< 75 μg/m3
|
6.3 (90/1420)
|
1
| |
1
| |
|
Non-smokers
|
≥ 75 μg/m3
|
6.4 (42/653)
|
1.00 (0.67, 1.46)
| |
1.10 (0.74, 1.64)
| |
|
Smokers
|
< 75 μg/m3
|
18.4 (156/847)
|
2.29 (1.56, 3.37)
|
1
|
2.22 (1.51, 3.27)
|
1
|
|
Smokers
|
≥ 75 μg/m3
|
24.4 (119/487)
|
2.96 (2.04, 4.31)
|
1.43 (1.09, 1.88) c
|
3.14 (2.15, 4.59)
|
1.36 (1.01, 1.83)c
|
- Smoking exposure: −, Non-smoker; + , smoker
- Annual mean PM2.5 exposure: −, < 75 μg/m3; + , ≥ 75 μg/m3
- aModel 1 was a univariate analysis with smoking exposure or annual mean PM2.5 as main effects and study sites as random effects
- bModel 2 was a multivariate analysis with adjustment for age, gender, residence, education, occupation, biomass use, parental history of respiratory diseases,body weight status, annual mean PM2.5 exposure/cigarette smoking, in addition to Model 1
- cThe OR predicted the likelihood for smokers who exposed to PM2.5 ≥ 75 μg/m3 to experience COPD compared to their counterparts who exposed to PM2.5 < 75 μg/m3 in this study
