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Epidemiol Health > Volume 43; 2021 > Article |
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Characteristics | Normal | Restrictive | Mild obstruction | Moderate obstruction | Severe and very severe obstruction | Total |
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Total (N/weighted N) | 20,598/16,084,557 | 2,995/2,268,300 | 1,761/1,303,355 | 1,833/1,332,349 | 191/142,568 | 27,378/21,131,129 |
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Age (yr) | 53.6 (0.1) | 58.5 (0.3) | 64.4 (0.3) | 62.8 (0.3) | 64.3 (0.8) | 55.4 (0.1) |
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Sex | ||||||
Male | 43.3 (0.4) | 52.3 (1.1) | 73.6 (1.2) | 74.7 (1.2) | 76.4 (3.5) | 48.3 (0.3) |
Female | 56.7 (0.4) | 47.7 (1.1) | 26.4 (1.2) | 25.3 (1.2) | 23.6 (3.5) | 51.7 (0.3) |
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Residential area | ||||||
Urban | 80.0 (0.9) | 78.8 (1.3) | 74.5 (1.6) | 74.3 (1.6) | 65.6 (4.2) | 79.0 (0.9) |
Rural | 20.0 (0.9) | 21.2 (1.3) | 25.5 (1.6) | 25.7 (1.6) | 34.4 (4.2) | 21.0 (0.9) |
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Education level | ||||||
≤Elementary school | 23.4 (0.4) | 30.6 (1.1) | 40.8 (1.4) | 39.7 (1.4) | 55.7 (4.3) | 26.5 (0.4) |
Middle school | 14.2 (0.3) | 15.8 (0.8) | 16.2 (1.0) | 17.9 (1.1) | 19.8 (3.7) | 14.7 (0.3) |
High school | 34.9 (0.5) | 31.3 (1.1) | 27.5 (1.3) | 26.1 (1.2) | 17.7 (3.3) | 33.4 (0.4) |
≥College | 27.5 (0.5) | 22.4 (1.1) | 15.6 (1.0) | 16.2 (1.1) | 6.8 (1.8) | 25.4 (0.5) |
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Household income | ||||||
Lower | 23.2 (0.4) | 24.7 (1.0) | 23.3 (1.2) | 27.5 (1.3) | 35.4 (4.0) | 23.7 (0.4) |
Lower middle | 25.4 (0.4) | 25.0 (1.0) | 26.7 (1.3) | 24.5 (1.2) | 23.0 (3.6) | 25.4 (0.4) |
Upper middle | 25.6 (0.4) | 25.1 (1.0) | 26.1 (1.3) | 25.1 (1.2) | 27.3 (4.1) | 25.6 (0.4) |
Upper | 25.8 (0.5) | 25.2 (1.0) | 23.9 (1.3) | 22.9 (1.2) | 14.3 (2.9) | 25.4 (0.5) |
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Smoking status | ||||||
No | 81.2 (0.4) | 79.8 (0.9) | 70.3 (1.3) | 66.9 (1.3) | 69.4 (4.0) | 79.4 (0.3) |
Current (≥5 packs in a lifetime) | 18.8 (0.4) | 20.2 (0.9) | 29.7 (1.3) | 33.1 (1.3) | 30.6 (4.0) | 20.6 (0.3) |
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Obesity1 | ||||||
Underweight | 1.3 (0.1) | 1.7 (0.3) | 1.5 (0.5) | 3.6 (0.5) | 10.9 (2.7) | 1.6 (0.1) |
Normal | 62.3 (0.4) | 45.1 (1.2) | 69.8 (1.4) | 63.7 (1.3) | 64.1 (4.1) | 61.0 (0.4) |
Obesity | 36.4 (0.4) | 53.2 (1.2) | 28.7 (1.3) | 32.7 (1.3) | 25.0 (3.7) | 37.4 (0.4) |
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Temperature (°C)2 | 12.8 (0.3) | 12.0 (0.4) | 12.8 (0.4) | 12.8 (0.4) | 13.2 (0.9) | 12.7 (0.3) |
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Relative humidity (%) | 68.2 (0.3) | 67.9 (0.5) | 68.8 (0.5) | 69.0 (0.5) | 68.5 (1.4) | 68.3 (0.3) |
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Pollutant 2-yr lag3 | ||||||
PM10 (μg/m3) | 50.2 (0.1) | 50.5 (0.2) | 49.6 (0.2) | 50.2 (0.2) | 49.2 (0.6) | 50.2 (0.1) |
PM2.5 (μg/m3) | 25.3 (0.1) | 25.5 (0.1) | 25.2 (0.1) | 25.4 (0.1) | 25.3 (0.4) | 25.3 (0.1) |
SO2 (ppb) | 5.0 (0.0) | 4.9 (0.0) | 5.0 (0.1) | 5.0 (0.1) | 4.7 (0.2) | 5.0 (0.0) |
NO2 (ppb) | 24.1 (0.1) | 23.9 (0.3) | 23.2 (0.3) | 23.4 (0.3) | 21.0 (0.8) | 24.0 (0.1) |
CO (ppb) | 492.6 (1.6) | 497.0 (2.7) | 480.9 (3.3) | 488.1 (2.8) | 472.1 (8.9) | 491.9 (1.5) |
O3 (ppb) | 24.6 (0.1) | 24.6 (0.1) | 25.0 (0.1) | 24.7 (0.1) | 25.4 (0.3) | 24.7 (0.1) |
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Pulmonary function4 | 76.1 (0.3) | 10.7 (0.2) | 6.2 (0.2) | 6.3 (0.2) | 0.7 (0.1) | - |
FVC (L) | 3.6 (0.0) | 2.8 (0.0) | 4.0 (0.0) | 3.3 (0.0) | 2.6 (0.1) | 3.5 (0.0) |
FVCp (%) | 95.3 (0.1) | 74.0 (0.1) | 100.0 (0.3) | 82.7 (0.3) | 65.9 (1.0) | 92.3 (0.1) |
FEV1 (L) | 2.9 (0.0) | 2.3 (0.0) | 2.6 (0.0) | 2.1 (0.0) | 1.2 (0.0) | 2.7 (0.0) |
FEV1p (%) | 96.0 (0.1) | 77.5 (0.2) | 90.5 (0.2) | 69.4 (0.2) | 41.0 (0.6) | 91.6 (0.1) |
FEV1/FVC | 0.8 (0.0) | 0.8 (0.0) | 0.7 (0.0) | 0.6 (0.0) | 0.5 (0.0) | 0.8 (0.0) |
Values are presented as mean (standard error) for continuous variables or % (standard error of %) for categorical variables.
PM10, particulate matter less than 10 μm in diameter; PM2.5, particulate matter less than 2.5 μm in diameter; SO2, sulfur dioxide; NO2, nitrogen oxide; CO, carbon monoxide; O3, ozone; ppb, parts per billion; BMI, body mass index; FVC, forced vital capacity; FVCp, percent predicted FVC; FEV1, forced expiratory volume in 1 second; FEV1p, percent predicted FEV1.
2 Temperature and relative humidity were measured in the residential area at the date of the survey.
3 Exposure to each pollutant with a 2-year lag was defined as the mean value of the time-series data for each air pollutant at the residential address from 2 years before the survey date.
4 The pulmonary function groups were defined as follows: normal (FEV1/FVC ≥0.7 and FVCp ≥80%), restrictive (FEV1/FVC ≥0.7 and FVCp <80%), mild obstruction (FEV1/FVC <0.7 and FEV1p ≥80%), moderate obstruction (FEV1/FVC <0.7 and 50≤FEV1p<80%), and severe and very severe obstruction (FEV1/FVC <0.7 and FEV1p <50%).
Variables | Model3 | Pulmonary function, OR (95% CI) | p for trend1 | |||
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Q1 | Q2 | Q3 | Q4 | |||
PM10 median (Max) (μg/m3) | 43.3 (46.2) | 47.9 (49.2) | 51.4 (53.7) | 57.7 (72.9) | ||
Total | Restrictive | 1.000 (reference) | 0.947 (0.811, 1.105) | 0.966 (0.830, 1.124) | 1.203 (1.036, 1.396) | 0.011 |
COPD | 1.000 (reference) | 0.984 (0.857, 1.129) | 1.070 (0.931, 1.230) | 1.086 (0.945, 1.247) | 0.137 | |
≥Moderate obstruction | 1.000 (reference) | 1.036 ([0.876, 1.226) | 1.109 (0.939, 1.309) | 1.189 (1.009, 1.401) | 0.028 | |
Male | Restrictive | 1.000 (reference) | 1.018 (0.830, 1.249) | 0.865 (0.697, 1.073) | 1.272 (1.044, 1.551) | 0.052 |
COPD | 1.000 (reference) | 1.020 (0.859, 1.211) | 1.077 (0.905, 1.282) | 1.038 (0.872, 1.236) | 0.557 | |
≥Moderate obstruction | 1.000 (reference) | 1.057 (0.859, 1.301) | 1.082 (0.882, 1.326) | 1.135 (0.921, 1.398) | 0.236 | |
Female | Restrictive | 1.000 (reference) | 0.879 (0.710, 1.088) | 1.075 (0.876, 1.320) | 1.140 (0.928, 1.401) | 0.060 |
COPD | 1.000 (reference) | 0.895 (0.717, 1.117) | 1.044 (0.835, 1.304) | 1.197 (0.945, 1.516) | 0.067 | |
≥Moderate obstruction | 1.000 (reference) | 0.980 (0.730, 1.315) | 1.167 (0.875, 1.556) | 1.354 (0.998, 1.837) | 0.027 | |
Non-smokers4 | Restrictive | 1.000 (reference) | 0.905 (0.765, 1.071) | 0.948 (0.805, 1.115) | 1.139 (0.968, 1.339) | 0.078 |
COPD | 1.000 (reference) | 0.961 (0.824, 1.120) | 1.047 (0.896, 1.224) | 1.132 (0.967, 1.327) | 0.072 | |
≥Moderate obstruction | 1.000 (reference) | 1.053 (0.866, 1.282) | 1.198 (0.988, 1.452) | 1.320 (1.091, 1.598) | 0.002 | |
Current smokers5 | Restrictive | 1.000 (reference) | 1.165 (0.824, 1.649) | 1.061 (0.749, 1.504) | 1.493 (1.082, 2.060) | 0.023 |
COPD | 1.000 (reference) | 1.025 (0.783, 1.342) | 1.099 (0.844, 1.433) | 0.964 (0.747, 1.245) | 0.863 | |
≥Moderate obstruction | 1.000 (reference) | 0.994 (0.721, 1.371) | 0.901 (0.654, 1.240) | 0.921 (0.675, 1.256) | 0.506 | |
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PM2.5 median (Max) (μg/m3) | 22.1 (23.3) | 24.1 (25.0) | 25.8 (26.9) | 29.0 (38.8) | ||
Total | Restrictive | 1.000 (reference) | 1.125 (0.969, 1.307) | 1.105 (0.948, 1.289) | 1.283 (1.101, 1.495) | 0.003 |
COPD | 1.000 (reference) | 1.029 (0.897, 1.181) | 1.120 (0.972, 1.291) | 1.039 (0.908, 1.189) | 0.362 | |
≥Moderate obstruction | 1.000 (reference) | 1.090 (0.921, 1.291) | 1.137 (0.958, 1.350) | 1.136 (0.962, 1.342) | 0.116 | |
Male | Restrictive | 1.000 (reference) | 1.090 (0.884, 1.343) | 1.080 (0.874, 1.335) | 1.290 (1.044, 1.595) | 0.026 |
COPD | 1.000 (reference) | 1.079 (0.909, 1.282) | 1.091 (0.911, 1.307) | 1.005 (0.849, 1.190) | 0.918 | |
≥Moderate obstruction | 1.000 (reference) | 1.157 (0.935, 1.431) | 1.107 (0.894, 1.372) | 1.134 (0.919, 1.399) | 0.326 | |
Female | Restrictive | 1.000 (reference) | 1.148 (0.944, 1.396) | 1.119 (0.910, 1.376) | 1.270 (1.045, 1.543) | 0.027 |
COPD | 1.000 (reference) | 0.922 (0.724, 1.175) | 1.167 (0.942, 1.446) | 1.107 (0.883, 1.389) | 0.146 | |
≥Moderate obstruction | 1.000 (reference) | 0.944 (0.689, 1.292) | 1.186 (0.892, 1.577) | 1.148 (0.851, 1.548) | 0.189 | |
Non-smokers4 | Restrictive | 1.000 (reference) | 1.150 (0.981, 1.350) | 1.117 (0.947, 1.316) | 1.259 (1.072, 1.478) | 0.010 |
COPD | 1.000 (reference) | 1.027 (0.878, 1.201) | 1.118 (0.955, 1.309) | 1.068 (0.914, 1.247) | 0.259 | |
≥Moderate obstruction | 1.000 (reference) | 1.080 (0.887, 1.315) | 1.163 (0.956, 1.414) | 1.174 (0.971, 1.419) | 0.070 | |
Current smokers5 | Restrictive | 1.000 (reference) | 1.009 (0.712, 1.431) | 1.028 (0.734, 1.439) | 1.341 (0.958, 1.877) | 0.085 |
COPD | 1.000 (reference) | 1.007 (0.769, 1.320) | 1.118 (0.850, 1.471) | 0.951 (0.734, 1.232) | 0.886 | |
≥Moderate obstruction | 1.000 (reference) | 1.090 (0.774, 1.534) | 1.068 (0.762, 1.498) | 1.024 (0.737, 1.423) | 0.948 | |
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NO2 median (Max) (ppb) | 12.0 (16.3) | 18.8 (21.3) | 25.9 (32.0) | 35.5 (41.2) | ||
Total | Restrictive | 1.000 (reference) | 0.932 (0.788, 1.102) | 0.935 (0.794, 1.101) | 0.951 (0.798, 1.133) | 0.681 |
COPD | 1.000 (reference) | 0.988 (0.853, 1.146) | 1.082 (0.928, 1.261) | 1.154 (0.988, 1.348) | 0.031 | |
≥Moderate obstruction | 1.000 (reference) | 1.060 (0.889, 1.263) | 1.112 (0.927, 1.334) | 1.187 (0.979, 1.439) | 0.075 | |
Male | Restrictive | 1.000 (reference) | 0.845 (0.669, 1.067) | 0.920 (0.733, 1.154) | 0.892 (0.695, 1.144) | 0.610 |
COPD | 1.000 (reference) | 0.994 (0.829, 1.191) | 1.043 (0.870, 1.250) | 1.134 (0.935, 1.376) | 0.151 | |
≥Moderate obstruction | 1.000 (reference) | 1.088 (0.876, 1.351) | 1.041 (0.836, 1.297) | 1.206 (0.949, 1.532) | 0.195 | |
Female | Restrictive | 1.000 (reference) | 1.040 (0.846, 1.280) | 0.955 (0.775, 1.176) | 1.029 (0.824, 1.285) | 0.978 |
COPD | 1.000 (reference) | 0.982 (0.766, 1.259) | 1.164 (0.867, 1.562) | 1.203 (0.911, 1.588) | 0.096 | |
≥Moderate obstruction | 1.000 (reference) | 1.014 (0.735, 1.400) | 1.281 (0.901, 1.822) | 1.183 (0.824, 1.696) | 0.200 | |
Non-smokers4 | Restrictive | 1.000 (reference) | 0.983 (0.826, 1.171) | 0.962 (0.812, 1.141) | 0.976 (0.814, 1.169) | 0.762 |
COPD | 1.000 (reference) | 1.148 (0.972, 1.355) | 1.144 (0.955, 1.371) | 1.331 (1.113, 1.593) | 0.004 | |
≥Moderate obstruction | 1.000 (reference) | 1.222 (0.992, 1.506) | 1.201 (0.967, 1.493) | 1.384 (1.105, 1.733) | 0.012 | |
Current smokers5 | Restrictive | 1.000 (reference) | 0.735 (0.511, 1.057) | 0.827 (0.575, 1.189) | 0.860 (0.576, 1.284) | 0.773 |
COPD | 1.000 (reference) | 0.674 (0.506, 0.898) | 0.930 (0.699, 1.237) | 0.801 (0.592, 1.084) | 0.698 | |
≥Moderate obstruction | 1.000 (reference) | 0.758 (0.538, 1.069) | 0.924 (0.659, 1.295) | 0.841 (0.575, 1.230) | 0.731 | |
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CO median (Max) (ppb) | 373.7 (415.2) | 454.3 (500.8) | 531.9 (555.1) | 588.0 (865.1) | ||
Total | Restrictive | 1.000 (reference) | 1.004 (0.861, 1.169) | 0.995 (0.855, 1.157) | 1.292 (1.110, 1.504) | 0.001 |
COPD | 1.000 (reference) | 0.925 (0.803, 1.067) | 1.001 (0.873, 1.149) | 1.027 (0.892, 1.182) | 0.501 | |
≥Moderate obstruction | 1.000 (reference) | 1.074 (0.905, 1.275) | 1.113 (0.942, 1.315) | 1.140 (0.956, 1.358) | 0.135 | |
Male | Restrictive | 1.000 (reference) | 0.964 (0.784, 1.186) | 1.029 (0.828, 1.278) | 1.273 (1.029, 1.577) | 0.018 |
COPD | 1.000 (reference) | 0.953 (0.800, 1.135) | 1.010 (0.847, 1.203) | 0.989 (0.829, 1.179) | 0.941 | |
≥Moderate obstruction | 1.000 (reference) | 1.097 (0.887, 1.356) | 1.122 (0.913, 1.380) | 1.079 (0.866, 1.344) | 0.479 | |
Female | Restrictive | 1.000 (reference) | 1.043 (0.852, 1.277) | 0.961 (0.786, 1.175) | 1.322 (1.091, 1.602) | 0.013 |
COPD | 1.000 (reference) | 0.860 (0.682, 1.085) | 0.972 (0.775, 1.218) | 1.112 (0.866, 1.429) | 0.308 | |
≥Moderate obstruction | 1.000 (reference) | 1.011 (0.755, 1.354) | 1.064 (0.792, 1.428) | 1.294 (0.939, 1.783) | 0.121 | |
Non-smokers4 | Restrictive | 1.000 (reference) | 1.042 (0.882, 1.230) | 0.997 (0.848, 1.171) | 1.320 (1.125, 1.547) | 0.002 |
COPD | 1.000 (reference) | 1.000 (0.856, 1.169) | 1.042 (0.894, 1.214) | 1.121 (0.952, 1.320) | 0.150 | |
≥Moderate obstruction | 1.000 (reference) | 1.217 (1.004, 1.474) | 1.239 (1.022, 1.502) | 1.306 (1.069, 1.596) | 0.012 | |
Current smokers5 | Restrictive | 1.000 (reference) | 0.853 (0.608, 1.198) | 0.998 (0.712, 1.400) | 1.197 (0.847, 1.693) | 0.182 |
COPD | 1.000 (reference) | 0.759 (0.582, 0.989) | 0.908 (0.686, 1.200) | 0.814 (0.624, 1.063) | 0.304 | |
≥Moderate obstruction | 1.000 (reference) | 0.801 (0.581, 1.104) | 0.884 (0.641, 1.218) | 0.836 (0.602, 1.160) | 0.404 |
OR, odds ratio; CI, confidence interval; Max, maximum; Q, quartile; PM10, particulate matter less than 10 μm in diameter; PM2.5, particulate matter less than 2.5 μm in diameter; NO2, nitrogen oxide; CO, carbon monoxide; ppb, parts per billion; COPD, chronic obstructive pulmonary disease.
1 Model for restrictive lung disease: normal as a reference (total, n=20,598; male, n=7,782; female, n=12,816; non-smokers, n=17,408; current smokers, n=3,190) and the restrictive lung disease group as the event (total, n=2,995; male, n=1,439; female, n=1,556; non-smokers, n=2,480; current smokers, n=515) as the dependent variable; Model for COPD: normal as reference versus COPD as the event (total, n=3,785; male, n=2,759; female, n=1,026; non-smokers, n=2,681; current smokers, n=1,104); Model for ≥moderate obstruction: normal as reference and moderate, severe, and very severe obstruction groups as the event (total, n=2,024; male, n=1,475; female, n=549; non-smokers, n=1,413; current smokers, n=611).
2 The covariates were age, sex, residential area, education level, household income, smoking status, obesity, temperature, and relative humidity.
Variables (lag period)2 | FVCp | FEV1p | FEV1/FVC | |||
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Beta | p-value | Beta | p-value | Beta | p-value | |
PM10 (2 yr) | ||||||
Q2 | −0.041 | 0.886 | 0.178 | 0.573 | 0.002 | 0.145 |
Q3 | −0.311 | 0.256 | −0.275 | 0.363 | 0.000 | 0.797 |
Q4 | −0.928 | 0.001 | −0.672 | 0.027 | 0.002 | 0.269 |
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PM2.5 (2 yr) | ||||||
Q2 | −0.524 | 0.059 | −0.600 | 0.052 | −0.001 | 0.471 |
Q3 | −0.282 | 0.306 | −0.659 | 0.032 | −0.003 | 0.028 |
Q4 | −1.290 | <0.001 | −1.205 | <0.001 | 0.000 | 0.990 |
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NO2 (2 yr) | ||||||
Q2 | −0.310 | 0.333 | −0.404 | 0.232 | 0.000 | 0.872 |
Q3 | −0.343 | 0.260 | −0.592 | 0.076 | −0.001 | 0.405 |
Q4 | −0.509 | 0.118 | −0.864 | 0.014 | −0.003 | 0.165 |
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CO (2 yr) | ||||||
Q2 | −0.815 | 0.004 | −0.608 | 0.056 | 0.002 | 0.326 |
Q3 | −0.828 | 0.002 | −0.851 | 0.005 | 0.000 | 0.906 |
Q4 | −1.460 | <0.001 | −1.128 | <0.001 | 0.002 | 0.115 |
PM10, particulate matter less than 10 μm in diameter; PM2.5, particulate matter less than 2.5 μm in diameter; NO2, nitrogen oxide; CO, carbon monoxide; FVC, forced vital capacity; FVCp, percent predicted FVC; FEV1, forced expiratory volume in 1 second; FEV1p, percent predicted FEV1; Q, quartile.
Variables | HR (95% CI) | p-value |
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Age (yr) | 1.114 (1.105, 1.123) | <0.001 |
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Sex | ||
Male | 1.791 (1.543, 2.078) | <0.001 |
Female | 1.000 (reference) | |
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Residential area | ||
Urban | 1.000 (reference) | |
Rural | 1.038 (0.906, 1.190) | 0.587 |
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Education level | ||
≤Elementary school | 1.000 (reference) | |
Middle school | 0.949 (0.790, 1.140) | 0.576 |
High school | 0.830 (0.692, 0.995) | 0.044 |
≥College | 0.669 (0.521, 0.858) | 0.002 |
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Household income | ||
Lower | 1.000 (reference) | |
Lower middle | 0.776 (0.658, 0.914) | 0.003 |
Upper middle | 0.605 (0.507, 0.722) | <0.001 |
Upper | 0.716 (0.599, 0.857) | <0.001 |
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Smoking status | ||
No | 1.000 (reference) | |
Current (≥5 packs in a lifetime) | 1.625 (1.391, 1.897) | <0.001 |
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Obesity | ||
Underweight | 1.591 (1.164, 2.174) | 0.004 |
Normal | 1.000 (reference) | |
Obesity | 0.841 (0.732, 0.966) | 0.015 |
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Temperature (°C) | 1.004 (0.998, 1.011) | 0.199 |
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Relative humidity (%) | 0.996 (0.991, 1.001) | 0.091 |
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Pulmonary function2 | ||
Normal | 1.000 (reference) | |
Restrictive | 1.585 (1.332, 1.886) | <0.001 |
Mild obstruction | 1.278 (1.052, 1.551) | 0.013 |
Moderate obstruction | 1.415 (1.170, 1.710) | <0.001 |
Severe and very severe obstruction | 1.896 (1.293, 2.782) | 0.001 |
FVC, forced vital capacity; FVCp, percent predicted FVC; FEV1, forced expiratory volume in 1 second; FEV1p, percent predicted FEV1.
1 Cox models show hazard ratios for pulmonary function groups after adjustment for age, sex, residential area, education level, household income, smoking status, obesity, temperature, and relative humidity.
2 The pulmonary function groups were defined as follows: normal (FEV1/FVC ≥0.7 and FVCp ≥80%), restrictive (FEV1/FVC ≥0.7 and FVCp < 80%), mild obstruction (FEV1/FVC <0.7 and FEV1p ≥80%), moderate obstruction (FEV1/FVC <0.7 and 50≤FEV1p<80%), and severe and very severe obstruction (FEV1/FVC <0.7 and FEV1p <50%).
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