Table 4. Multivariate analyses for overall survival by Cox regression model.

	P value	Exp(B)	RR 95% CI
			Lower	Upper
Age	0.372	1.567	0.584	4.206
Gender	0.844	0.918	0.392	2.151
Ulcer history	0.551	0.74	0.274	1.994
Position	0.856	1.095	0.413	2.9
Clinical stage	0.001*	5.326	1.986	14.281
Clark level	0.027*	2.706	1.121	6.533
Breslow thickness	0.351	0.661	0.277	1.578
Klotho	0.022*	0.283	0.096	0.836

^*P<0.05