Table 7.

Kaplan Meier and Cox Proportional Hazards Analysis for Survival

		% Survival (95%CI)
Overall (3 NAs)	1-year	89.3 (86.1 – 92.6)
	3-year	66.0 (61.0 – 71.5)
	5-year	56.1 (50.6 – 62.1)

Variable	Univariable regression		Multivariable model
	HR (95% CI)	P	HR (95% CI)	P
Age (per decade increase in age)	1.27 (1.14 – 1.41)	<0.001 *	1.27 (1.13 – 1.44)	<0.001*
Depth (deep vs superficial)	2.79 (1.66 – 4.68)	<0.001 *	2.58 (1.43 – 4.68)	0.002 *
Maximal Diameter (cm)	1.05 (1.03 – 1.07)	<0.001 *	1.04 (1.02 – 1.06)	<0.001 *
Margin
Micro + vs Negative	1.81 (1.14 – 2.89)	0.01 *	1.95 (1.20 – 3.17)	0.007 *
Gross + vs Negative	1.97 (1.06 – 3.67)	0.03 *	2.01 (1.03 – 3.89)	0.04 *
Radiotherapy (yes vs no)	1.18 (0.86 – 1.61)	0.30	0.99 (0.71 – 1.39)	0.96
Chemotherapy (yes vs no)	0.90 (0.66 – 1.23)	0.51	0.85 (0.60 – 1.21)	0.38
Treating institution	n/a	0.015	n/a	1

(†Variables in model selected based on a priori determination (CT and RT) and univariable cox analysis with p<0.10), ††Controlling for random effects of treating institution)

(n=343, 27 observations deleted due to missingness)