Table 1 Lifetime smoky coal users by stove use history in Xuanwei, China, 1976–1996
From: Portable stove use is associated with lower lung cancer mortality risk in lifetime smoky coal users
No stove change ( N =4364) | Change to portable stove ( N =4054) | Total subjects ( N =8418) | |
|---|---|---|---|
Men and women | |||
Person-years | 60 322.77 | 78 195.92 | 138 518.69 |
Age as of 1 January 1976 | 42.4 (±11.0) | 37.2 (±10.4) | 39.9 (±11.0) |
Age at exit from follow-up | 56.2 (±9.9) | 56.2 (±9.4) | 56.3 (±9.7) |
Lung cancer death, 1976–1996 | 810 (18.6%) | 264 (6.5%) | 1074 (12.8%) |
Died without lung cancer during follow-up | 1483 (34.0%) | 510 (12.6%) | 1993 (23.7%) |
Alive in 1996 | 2071 (47.5%) | 3280 (80.9%) | 5351 (63.6%) |
Age at stove improvement | Not applicable | 32.5 (±12.8) | Not applicable |
Time from stove improvement until exit from follow-up | Not applicable | 24.0 (±10.9) | Not applicable |
People in household, first residence | 4.9 (±1.7) | 5.3 (±1.4) | 5.1 (±1.6) |
Rooms in home, first residence | 1.5 (±0.8) | 1.4 (±0.7) | 1.4 (±0.7) |
Han nationality | 4206 (96.4%) | 4004 (98.8%) | 8210 (97.5%) |
Literate | 1323 (30.3%) | 1759 (43.4%) | 3082 (36.6%) |
History of | |||
Chronic bronchitis | 940 (21.5%) | 356 (8.8%) | 1296 (15.4%) |
Emphysaema | 253 (5.8%) | 71 (1.8%) | 324 (3.9%) |
Tuberculosis | 77 (1.8%) | 19 (0.5%) | 96 (1.1%) |
People with ⩾7 waking hours indoors per daya | 2170 (63.9%) | 1237 (42.6%) | 3407 (54.1%) |
Smoky coal | |||
Tons used lifetime | 160.0 (±57.8) | 144.1 (±53.7) | 152.3 (±56.4) |
Tons used annually | 3.0 (±0.9) | 2.8 (±0.9) | 2.9 (±0.9) |
Work other than farming | 694 (15.9%) | 1211 (29.9%) | 1905 (22.6%) |
Coal miner | 167 (3.8%) | 18 (0.4%) | 185 (2.2%) |
Driver | 24 (0.6%) | 34 (0.8%) | 58 (0.7%) |
Construction worker | 141 (3.2%) | 407 (10.0%) | 548 (6.5%) |
Men only b | |||
Total included in analysis | 2303 (52.8%) | 2082 (51.4%) | 4385 (52.1%) |
Person-years | 32 132.00 | 39 963.67 | 72 095.67 |
Lung cancer in first-degree relatives | 140 (6.1%) | 194 (9.3%) | 334 (7.6%) |
Tobacco smoking: | |||
Ever | 2040 (88.6%) | 1921 (92.3%) | 3961 (90.3%) |
Years, in ever smokers | 35.2 (±10.7) | 34.5 (±9.6) | 34.9 (±10.2) |
Age started, in ever smokers | 21.2 (±3.8) | 21.8 (±3.9) | 21.5 (±3.9) |
Ever quit, in ever smokers | 35 (1.5%) | 43 (2.1%) | 78 (1.8%) |
Filtered cigarettes per day, in ever smokers | 10.8 (±7.2) | 13.0 (±7.9) | 11.8 (±7.6) |
Non-filtered cigarettes per day, in ever smokers | 13.2 (±6.0) | 15.5 (±5.8) | 14.5 (±6.0) |
Dry pipes (cigars) per month, in ever smokers | 11.7 (±6.9) | 11.6 (±6.1) | 11.7 (±6.6) |
Water pipes per month, in ever smokers | 6.7 (±4.9) | 6.5 (±8.2) | 6.7 (±5.7) |
Cooking | |||
Ever | 331 (14.4%) | 226 (10.9%) | 597 (13.6%) |
Years, in ever cookers | 24.7 (±13.6) | 24.4 (±11.9) | 24.6 (±12.8) |
Age started, in ever cookers | 25.3 (±14.0) | 27.6 (±11.9) | 26.3 (±13.1) |
Women only b | |||
Total included in analysis | 2061 (47.2%) | 1972 (48.6%) | 4033 (47.9%) |
Person-years | 28 190.76 | 38 232.25 | 66 423.01 |
Lung cancer in first-degree relatives | 92 (4.5%) | 136 (6.9%) | 228 (5.7%) |
Ever smoked tobacco | 16 (0.8%) | 6 (0.3%) | 22 (0.5%) |
Cooking | |||
Ever | 1992 (96.7%) | 1934 (98.1%) | 3926 (97.3%) |
Years, in ever cookers | 34.6 (±10.4) | 32.1 (±9.9) | 33.4 (±10.2) |
Age started, in ever cookers | 16.8 (±4.4) | 18.7 (±3.1) | 17.8 (±4.0) |
