Table 4.

Risk factors for PTB in patients with lung cancer involving different cell types.

Variable	Non-small cell		Small cell
	AHR (95% CI)	AHR1 (95% CI)	AHR (95% CI)	AHR1 (95% CI)
Sex
Male vs. Female	2.0*(1.7-2.3)	1.7*(1.5-2.0)	1.7(0.8-3.6)	1.7(0.8-3.8)
Age(years)
<50	Ref	Ref	Ref	Ref
50-59	1.2(0.9-1.5)	1.2(0.9-1.5)	1.0(0.4-2.5)	1.1(0.4-2.7)
60-69	1.6*(1.2-2.0)	1.5*(1.2-1.9)	0.9(0.4-2.2)	0.9(0.4-2.3)
≥70	2.3*(1.8-2.9)	1.9*(1.5-2.4)	1.5(0.7-3.6)	1.4(0.6-3.3)
Clinical stage
I	Ref	Ref	Ref	Ref
II	1.4*(1.1-1.8)	1.2(0.9-1.6)	1.6(0.3-7.0)	1.2(0.2-6.6)
III	1.6*(1.3-1.9)	1.2(1.0-1.5)	1.1(0.3-3.6)	0.9(0.3-2.9)
IV	1.4*(1.1-1.7)	0.9(0.7-1.1)	1.2(0.4-3.9)	0.7(0.2-2.4)
Operation	1.1(0.9-1.3)	1.6*(1.3-1.9)	0.5(0.1-1.9)	0.6(0.1-2.2)
Chemotherapy	1.0(0.9-1.1)	1.2*(1.0-1.3)	1.3(0.8-2.4)	2.4*(1.4-4.4)
Radiation	1.0(0.9-1.2)	1.0(0.9-1.2)	0.9(0.6-1.3)	1.1(0.7-1.6)
Comorbidity
Diabetes	0.9(0.8-1.1)	0.9(0.8-1.0)	1.2(0.8-1.8)	1.1(0.7-1.7)
COPD	1.1(0.9-1.2)	1.0(0.9-1.2)	1.2(0.8-1.8)	1.1(0.7-1.7)
Renal disease	1.0(0.7-1.4)	0.9(0.7-1.2)	0.6(0.2-1.9)	0.4(0.1-1.6)
Pneumoconiosis	3.3*(2.0-5.6)	3.0*(1.8-5.1)	0.9(0.1-15.7)	-
Hypertension	0.9(0.7-1.0)	0.8(0.7-1.0)	0.9(0.5-1.5)	0.9(0.5-1.5)
Dyslipidemia	0.6(0.4-1.1)	0.7(0.4-1.1)	1.9(0.6-5.7)	1.8(0.5-6.3)
Ischemic Heart Disease	0.9(0.6-1.2)	0.8(0.6-1.1)	0.7(0.3-2.0)	0.6(0.2-2.0)
Cerebrovascular Disease	1.1(0.7-1.7)	0.9(0.6-1.4)	0.3(<0.01-4.1)	-
Smoking, yes	1.3*(1.1-1.5)	1.2(1.00-1.4)	1.1(0.5-2.5)	1.2(0.5-2.8)

1. The adjusted hazard ratio of PTB was derived from the subdistribution hazard ratio and competing mortality risk.

*. P-value less than 0.05.