Table 2.

Sex-specific Cox regression models of pneumonia death, Xuanwei, 1976–1996.

	Men		Women
Variable	HR (95% CI)	p-Value	HR (95% CI)	p-Value
Stove improvement (binary)
No	1		1
Yes	0.493 (0.312–0.779)	0.002	0.534 (0.323–0.882)	0.014
Time since stove improvement (ordinal)
No improvement	1		1
< 7 years	0.442 (0.220–0.889)	0.022	0.243 (0.095–0.627)	0.003
≥ 7 years to < 14 years	0.542 (0.304–0.968)	0.038	0.513 (0.258–1.019)	0.057
≥ 14 years	0.480 (0.230–1.000)	0.050	1.053 (0.552–2.007)	0.876
Ever use smokeless coal
No	1		1
Yes	1.522 (0.983–2.355)	0.060	1.444 (0.899–2.319)	0.129
Tons of coal used per yeara
< 2.57	1		1
≥ 2.57 to < 3.75	0.787 (0.502–1.234)	0.297	0.962 (0.573–1.614)	0.883
≥ 3.75	1.535 (0.981–2.404)	0.061	1.881 (1.141–3.101)	0.013
Years of coal usea
< 45 years	1		1
≥ 45 to < 57 years	1.094 (0.324–3.700)	0.885	2.334 (0.822–6.622)	0.111
≥ 57 years	2.482 (1.112–5.543)	0.027	2.668 (1.069–6.661)	0.035
Waking hours/day indoors through 20 years of age
< 7 hr	1		1
≥ 7 hr	0.896 (0.609–1.318)	0.577	1.237 (0.820–1.866)	0.311
No. of rooms in home
Every additional room	0.825 (0.634–1.074)	0.152	1.006 (0.770–1.313)	0.967
No. of people in home
Every additional person	1.095 (0.943–1.271)	0.234	1.180 (0.994–1.401)	0.058
Diagnosed chronic bronchitis, emphysema, or asthma
No	1		1
Yes	2.009 (1.316–3.066)	0.001	2.126 (1.347–3.356)	0.001
Cooking (ordinal)
< 20 years	—	—	1
≥ 20 to < 40 years	—	—	1.740 (0.275–10.990)	0.556
≥ 40 years	—	—	2.911 (0.467–18.131)	0.252
Cooking (binary)
No	1	—	—	—
Yes	0.705 (0.335–1.483)	0.357	—	—
Work as coal miner
No	1		—	—
Yes	1.022 (0.318–3.281)	0.971	—	—
Tobacco smoking
< 20 years	1		—	—
≥ 20 to < 40 years	0.935 (0.393–2.227)	0.879	—	—
≥ 40 years	1.639 (0.702–3.826)	0.254	—	—
Education
No education	1		1
With education	0.502 (0.287–0.876)	0.015	1.959 (0.959–4.001)	0.065

^aSmoky and smokeless coal types combined.