Table 1.
Characteristics of lifetime smoky and smokeless coal users among non-smoking women in Xuanwei, China, 1976–2011
| Lifetime smoky or smokeless coal usea | Lifetime and exclusive smoky coal use | Lifetime and exclusive smokeless coal use | |
|---|---|---|---|
| Follow-up characteristics | |||
| Number of lifetime coal users, retrospective + prospective follow-up (1976–2011), n | 16 323 | 11 188 | 1954 |
| Person-years of follow-up, 1976–2011, n | 439 003 | 283 638 | 45 051 |
| Mean age at entry into follow-up ± SD | 39.4 (10.6) | 39.4 (10.6) | 44.3 (11.2) |
| Mean age at end of follow-up ± SD | 65.3 (10.8) | 63.8 (10.8) | 66.3 (11.4) |
| Mortality characteristics | |||
| Mean age at death from ischaemic heart disease ± SD | 69.2 (11.6) | 68.2 (11.4) | 69.0 (11.4) |
| Mean age at death from stroke ± SD | 66.7 (11.5) | 64.5 (11.2) | 69.8 (11.1) |
| Ischaemic heart disease (ICD 410–414), n/age-adjusted mortality rate per 100 000 | 105/20.9 | 59/20.4 | 34/53.3 |
| Cerebrovascular disease (ICD 430–438), n/age-adjusted mortality rate per 100 000 | 363/68.1 | 243/73.2 | 89/138.2 |
| Stove use characteristics | |||
| Never stove improvement, n (%) | 1596 (10) | 1316 (12) | 241 (12) |
| Improvement to portable stove or stove with chimney, n (%) | 14 728 (90) | 9872 (88) | 1713 (88) |
| Other lifestyle and demographic characteristics | |||
| Mean no. of rooms in home during lifetime ± SD | 2 (1) | 2 (1) | 2 (1) |
| Mean no. of people in home during lifetime ± SD | 5 (1) | 5 (1) | 4 (2) |
| Mean no. of hours spent inside the home doing activities while awake ± SD | 7.3 (2.0) | 7.7 (1.9) | 7.7 (1.9) |
| Mean tons of coal used per year during follow-up ± SD | 3.2 (1.1) | 3.4 (1.0) | 2.8 (1.6) |
| Mean cumulative tons of coal used during follow-up ± SD | 42.5 (22.1) | 43.0 (22.0) | 32.0 (23.4) |
| Had any formal education (primary school or higher), n (%) | 3898 (23.9) | 2600 (23.2) | 286 (14.6) |
| Ever cooked food during lifetime, n (%) | 16 002 (98.0) | 10 940 (97.8) | 1933 (98.9) |
| Cumulative years of cooking during lifetime among ever cookers ± SD | 47.8 (11.0) | 46.7 (11.1) | 47.9 (11.5) |
a
Includes participants who used exclusively smoky or smokeless coal through to the end of their follow-up, as well as those who used a mix of smoky and smokeless coal through to the end of their follow-up.