Table 3. Multivariate Analysis of Characteristics Associated With Survival by Patient Lymph Node Ratio.

Characteristic	Lymph Node Ratio ≤0.31		Lymph Node Ratio >0.31
	Hazard Ratio (95% CI)	P Value	Hazard Ratio (95% CI)	P Value
Age	1.04 (1.02-1.05)	<.001	1.02 (0.10-1.04)	.10
Sex
Male	1.27 (0.96-1.67)	.10	1.36 (0.93-1.98)	.12
Female	1 [Reference]		1 [Reference]
Race
White	1 [Reference]		1 [Reference]
Black	1.61 (0.62-4.20)	.33	15.75 (1.87-132.69)	.01
Hispanic	Insufficient numbersa	NA	0.33 (0.12-0.91)	.03
Asian/Pacific Islander	1.09 (0.15-7.97)	.94	2.42 (0.29-19.88)	.41
Other/unknown	0.73 (0.18-3.01)	.66	2.02 (0.69-5.90)	.20
Insurance	Excludedb	NA
Private			1 [Reference]
Medicare			1.61 (0.92-2.84)	.10
Other government			3.44 (1.27-9.30)	.02
None			1.79 (0.40-8.02)	.45
Unknown			Insufficient numbersa	NA
Charlson/Deyo score			Excludedb	NA
0	1 [Reference]
1	1.46 (1.09-1.95)	.01
2	2.22 (1.31-3.79)	.003
≥3	0.90 (0.32-2.52)	.84
Pathologic T stage
1	1 [Reference]		1 [Reference]
2	1.65 (1.25-2.18)	<.001	1.47 (0.99-2.19)	.054
3	1.96 (1.24-3.11)	.004	1.63 (0.96-2.79)	.07
4	2.19 (1.43-3.36)	<.001	1.08 (0.50-2.34)	.85
Pathologic N stage
1A	1 [Reference]		1 [Reference]
1B	1.33 (0.86-2.07)	.21	5.04 (1.93-13.15)	.001
1, NOS	1.823 (1.283-2.591)	.001	4.68 (1.82-12.04)	.001
2/3	1.37 (0.70-2.66)	.36	4.04 (1.21-13.49)	.02
Lymph node ratio
<0.07	1 [Reference]
0.07-0.31	1.32 (0.10-1.75)	.054	NA	NA
Treatment combination
Surgery + RT	1 [Reference]		1 [Reference]
Surgery + CRT	0.93 (0.65-1.33)	.69	0.61 (0.38-0.97)	.04
Surgery only	1.32 (0.10-1.74)	.053	1.34 (0.86-2.09)	.20

Abbreviations: CRT, chemoradiation therapy; NA, not applicable; NOS, not otherwise specified; RT, radiation therapy.

^aInsufficient subgroup event numbers for multivariate analysis.

^bVariable was excluded from multivariate model after Akaike information criterion minimization.