Table 3. Multivariate analysis for risk factors of lung cancer-specific mortality.

Variables	Unmatched				Matched
	HR	95% CI	P value		HR	95% CI	P value
IMA pathology	1.107	0.949–1.291	0.197		1.129	0.940–1.358	0.195
Age	1.020	1.018–1.022	<0.001		1.025	1.017–1.034	<0.001
Male sex	1.400	1.347–1.455	<0.001		1.550	1.312–1.831	<0.001
Race
Black	1
Other	0.767	0.697–0.843	<0.001		0.585	0.391–0.874	0.009
White	0.955	0.892–1.023	0.193		0.788	0.605–1.027	0.077
Marriage
Married/partner	1				1
Separated	1.151	1.101–1.204	<0.001		0.788	0.605–1.027	0.896
Single	1.153	1.080–1.230	<0.001		1.013	0.833–1.232	0.040
Unknown	0.996	1.891–1.114	0.948		1.319	1.013–1.718	0.282
Operation
Lobectomy	1				1
Pneumonectomy	1.310	1.209–1.419	<0.001		1.709	1.170–2.496	0.006
Sublobar	1.261	1.183–1.345	<0.001		1.620	1.270 –2.067	0.001
Radiation	1.361	1.291–1.435	<0.001		1.496	1.120–1.999	0.006
Insurance
Medicaid	1.239	1.123–1.366	<0.001
Uninsured	1.163	0.939–1.439	0.166
Unknown	1.190	1.125–1.259	<0.001
Location
Middle	1.016	0.930–1.110	0.719
Other	1.094	0.991–1.207	0.074
Upper	1.866	0.831–0.903	<0.001

CI, confidence interval; HR, hazards ratio; IMA, invasive mucinous adenocarcinoma.