Table 1.

Comparison of the baseline characteristics between the living and deceased groups with up-sampled data.

Variable	Balanced up-sampled data
	Living (N = 713)		Deceased (N = 713)		p-value
	n %		n %
Age (years)	62.51 ± 8.55		66.21 ± 8.31		< 0.001
< 65	393	63.3	228	36.7	< 0.001
≥ 65	320	39.8	485	60.2
Sex
Female	177	69.4	78	30.6	< 0.001
Male	537	45.8	635	54.2
Monthly income (USD)
≥ 3,000	207	69.5	91	30.5	< 0.001
< 3,000	506	44.9	622	55.1
Education
≥ High school degree	185	56.4	143	43.6	0.01
< High school degree	528	48.1	570	51.9
Currently married
Yes	655	50	656	50	0.92
No	58	50.4	57	49.6
FEV1/FVC	72.55 ± 15.11		65.77 ± 10.62		< 0.001
(FEV1/FVC)*100 ≥ 0.7	454	61.7	282	38.3	< 0.001
(FEV1/FVC)*100 < 0.7	259	37.5	431	62.5
Local tumor invasion
No	253	62.3	153	37.7	< 0.001
Yes	460	45.1	560	54.9
Regional lymph node metastasis
No	508	53.2	446	46.8	< 0.001
Yes	205	43.4	267	56.6
Stage
Stage 0–I	464	56.9	352	43.1	< 0.001
Stage II–III	249	40.8	361	59.2
Recurrence
No	630	62.8	373	37.2	< 0.001
Yes	83	19.6	340	80.4
Number of comorbidities
0	320	49	333	51	0.49
≥ 1	393	50.8	380	49.2
Treatment type
OP	435	51.7	417	48.6	< 0.001
OP + RT	41	37.6	68	62.4
OP + CT	193	53.6	167	46.4
OP + CT + RT	44	40	66	60
Time since diagnosis	2.93 ± 1.59		2.983 ± 1.68		0.29
≥ 3 years	307	53	272	47	0.06
< 3 years	406	47.9	441	52.1

OP, operation; RT, radiation therapy; CT, chemotherapy; FEV1/FVC, forced expiratory volume 1/forced vital capacity.