Table 5.

Multivariate analysis of factors affecting treatment effectiveness

	Assignment	β	SE	Wald	P value	HR	95% CI
Constant		1.761	0.403	19.111	0.000	5.821	-
Ulcer area before surgery	0 = ≤15.4 cm2; 1 = >15.4 cm2	0.883	0.522	2.868	0.090	2.419	0.870~6.725
Surgical approach	0 = Skin flap; 1 = Skin flap grafting + VSD	-1.220	0.519	5.532	0.019	0.295	0.107~0.816

Note: VSD, vacuum sealing drainage.