Table 1.
Demographic characteristics and exposures of study participants from the general Chinese population aged 40 years or older
| Total (n=66 752) | Men (n=33 137) | Women (n=33 615) | ||
|---|---|---|---|---|
| Age (years) | 54·9 (11·1) | 54·7 (10·9) | 55·0 (11·3) | |
| Body-mass index (kg/m2) | 24·7 (3·5) | 24·6 (3·5) | 24·8 (3·6) | |
| Residence | ||||
| Urban | 32 009/66 752 (48·2% [42·3–54·2]) | 14 624/33 137 (48·4% [42·4–54·4]) | 17 385/33 615 (48·0% [42·0–54·1]) | |
| Rural | 34 743/66 752 (51·8% [45·8–57·7]) | 18 513/33 137 (51·6% [45·6–57·6]) | 16 230/33 615 (52·0% [45·9–58·0]) | |
| Economic development | ||||
| Underdeveloped | 23 637/66 752 (34·4% [25·0–43·8]) | 12 106/33 137 (34·5% [25·3–43·7]) | 11 531/33 615 (34·3% [24·6–44·1]) | |
| Intermediately developed | 21 020/66 752 (24·2% [16·1–32·4]) | 10 137/33 137 (24·1% [15·9–32·3]) | 10 883/33 615 (24·4% [16·1–32·7]) | |
| Developed | 22 095/66 752 (41·4% [33·2–49·5]) | 10 894/33 137 (41·4% [33·5–49·3]) | 11 201/33 615 (41·3% [32·6–50·0]) | |
| Educational level | ||||
| Primary school and lower | 33 693/66 733 (47·1% [42·3–52·0]) | 14 454/33 130 (39·1% [34·8–43·4]) | 19 239/33 603 (55·3% [49·6–61·0]) | |
| Secondary school | 30 213/66 733 (48·4% [44·6–52·2]) | 17 068/33 130 (55·5% [52·1–58·8]) | 13 145/33 603 (41·2% [36·5–45·9]) | |
| Higher and further education | 2827/66 733 (4·5% [3·1–5·9]) | 1608/33 130 (5·4% [3·9–6·9]) | 1219/33 603 (3·5% [2·1–4·9]) | |
| Smoking status | ||||
| Never smoker | 40 070/66 567 (59·8% [58·3–61·4]) | 8296/33 077 (25·6% [23·3–27·8]) | 31 774/33 490 (94·8% [93·3–96·4]) | |
| Former smoker | 6438/66 567 (8·8% [8·2–9·4]) | 5988/33 077 (16·2% [15·2–17·3]) | 450/33 490 (1·2% [0·8–1·5]) | |
| Current smoker | 20 059/66 567 (31·4% [30·0–32·7]) | 18 793/33 077 (58·2% [56·1–60·3]) | 1266/33 490 (4·0% [2·7–5·3]) | |
| Smoking exposure* (pack-years) | ||||
| None to less than ten | 5801/24 775 (23·4% [22·1–24·7]) | 5029/23 201 (21·7% [20·4–23·0]) | 772/1574 (49·0% [45·1–53·0]) | |
| Ten to less than 25 | 6593/24 775 (26·6% [25·5–27·7]) | 6162/23 201 (26·5% [25·5–27·6]) | 431/1574 (27·4% [23·9–30·9]) | |
| 25 to less than 50 | 8610/24 775 (34·8% [33·7–35·8]) | 8321/23 201 (35·9% [34·8–36·9]) | 289/1574 (18·4% [15·6–21·1]) | |
| 50 or more | 3771/24 775 (15·2% [14·0–16·4]) | 3689/23 201 (15·9% [14·7–17·1]) | 82/1574 (5·2% [3·9–6·5]) | |
| Risk factors for COPD | ||||
| Hospital admission due to severe pulmonary disease in childhood | 1656/66 730 (2·5% [2·3–2·8]) | 819/33 129 (2·7% [2·3–3·1]) | 837/33 601 (2·4% [2·0–2·7]) | |
| Indoor exposure to biomass for cooking or heating | 28 914/66 686 (40·7% [34·0–47·4]) | 14 922/33 106 (40·7% [34·2–47·2]) | 13 992/33 580 (40·6% [33·5–47·8]) | |
| Indoor exposure to coal for cooking or heating | 22 881/66 676 (34·3% [27·1–41·6]) | 11 665/33 102 (34·5% [27·5–41·5]) | 11 216/33 574 (34·1% [26·4–41·8]) | |
| Exposure to dust or chemicals in the workplace | 29 808/66 722 (46·6% [40·0–49·1]) | 16 561/33 121 (49·7% [45·4–54·0]) | 13 247/33 601 (39·4% [34·3–44·4]) | |
| History of tuberculosis | 1247/66 730 (1·6% [1·4–1·9]) | 779/33 129 (2·1% [1·8–2·4]) | 468/33 601 (1·2% [1·0–1·4]) | |
| Spirometry | ||||
| Pre-bronchodilator FEV1 | 2·63 (0·70) | 2·99 (0·69) | 2·26 (0·49) | |
| Post-bronchodilator FEV1 | 2·68 (0·70) | 3·05 (0·69) | 2·31 (0·49) | |
| Pre-bronchodilator FVC | 3·45 (0·88) | 3·99 (0·78) | 2·89 (0·59) | |
| Post-bronchodilator FVC | 3·45 (0·87) | 3·99 (0·77) | 2·89 (0·58) | |
| Pre-bronchodilator FEV1:FVC | 76% (9) | 75% (9) | 78% (8) | |
| Post-bronchodilator FEV1:FVC | 78% (9) | 76% (9) | 80% (7) | |
Data are number exposed/total participants (% [95% CI]) or mean (SD). Weighted estimations were used. COPD=chronic obstructive pulmonary disease. FVC=forced vital capacity.
*
Only assessed in participants who were former or current smokers; data missing for 1722 participants.