Table 4. Multivariable exponential regression model for disease free survival.

	estimate	sd	z	HR	95% CI Lower	95% CI Upper	p value
(Intercept)	6.011	0.54	11.134
Age (each 5 years)	-0.048	0.038	-1.278	1.05	0.974	1.131	0.201
Pleural Invasion (yes.vs.no)	-0.249	0.186	-1.337	1.282	0.891	1.846	0.181
Tumor Size
T1a (baseline group)	-	-	-	1.0	-	-
T1b	-0.224	0.205	-1.093	1.251	0.837	1.869	0.274
T2a	-0.82	0.194	-4.222	2.271	1.552	3.324	<0.001
T2b	-0.599	0.285	-2.103	1.821	1.042	3.184	0.035
T3	-1.217	0.343	-3.549	3.376	1.724	6.611	<0.001
Performance status: some symptoms vs. normal	-0.061	0.155	-0.395	1.063	0.785	1.441	0.692
Performance status: < 50% of time in bed vs. normal	-1.521	0.36	-4.224	4.577	2.26	9.271	<0.001
Gender F vs. M	0.313	0.154	2.036	0.731	0.541	0.988	0.042
Histology: Squamous vs. Adenocarcinomas	0.009	0.188	0.047	0.991	0.686	1.432	0.963
Histology: Other non-small cell vs. Adenocarcinomas	0.092	0.203	0.452	0.912	0.612	1.359	0.651