Table 1 The basic characteristics of training and test sets of the 2,317 participants
Characteristics | Train set | Test set |
|---|---|---|
Age, years | 62.1 ± 12.6 | 61.9 ± 12.4 |
BMI, kg/m2 | ||
 BMI < 18.5 | 126(6.8%) | 37(8.0%) |
 18.5 ≤ BMI < 24 | 1009(54.4%) | 248(53.4%) |
 24 ≤ BMI < 28 | 561(30.3%) | 143(30.8%) |
 BMI ≥ 28 | 157(8.5%) | 36(7.8%) |
Gender | ||
 Male | 876(47.3%) | 238(51.3%) |
 Female | 977(52.7%) | 226(48.7%) |
Residence | ||
 Rural | 1521(82.1%) | 370(79.7%) |
 Urban | 332(17.9%) | 94(20.3%) |
Education years, years | ||
 0 | 496(26.8%) | 107(23.1%) |
 1–6 | 616(33.2%) | 161(34.7%) |
 7–12 | 650(35.1%) | 176(37.9%) |
 ≥ 13 | 91(4.9%) | 20(4.3%) |
Annual income in thousands, Chinese Yuan | ||
 < 50 | 645 (40.1%) | 162(40.2%) |
 50–100 | 646(40.2%) | 175(43.4%) |
 110–200 | 276(17.2%) | 57(14.1%) |
 210–300 | 25(1.6%) | 6(1.5%) |
 > 300 | 16(0.9%) | 3(0.7%) |
Marriage Status | ||
 Married | 1630(88.0%) | 398 (85.8%) |
 Divorced/Widowed | 163(8.8%) | 44(9.5%) |
 Never Married | 60 (3.2%) | 22(4.7%) |
Smoke Status | ||
 Current smoker | 279(15.1%) | 79(17.0%) |
 Former smoker | 123(6.6%) | 36(7.8%) |
 Non-smoker | 1451(78.3%) | 349(75.2%) |
Second-hand smoke exposure | ||
 Never | 1290(70.3%) | 321(69.3%) |
 Sometimes | 308(16.8%) | 72(15.6%) |
 1–2 days/week | 33(1.8%) | 3(0.6%) |
 3–5 days/week | 51(2.8%) | 16(3.5%) |
 Almost every day | 152(8.3%) | 51(11.0%) |
Drinking status | ||
 Never | 1316(71.0%) | 326(70.3%) |
 Sometimes | 157(8.5%) | 41(8.8%) |
 < 12 years | 29(1.6%) | 9(1.9%) |
 ≥ 12 years | 351(18.9%) | 88(19.0%) |
COPD | ||
 COPD | 373(20.1%) | 104(22.4%) |
 Non-COPD | 1480(79.9%) | 360(77.6%) |