Table 3.

Results of multivariate analysis

Factor	Risk ratio	95% CI		p value (chi-square)
		Lower	Upper
Age ≥40 years old	2.645	0.703	9.946	n.s.
Age ≥50 years old	3.418	0.926	12.615	n.s.
BMI ≥25 kg/m2	2.718	1.149	6.427	<0.05
BMI ≥28 kg/m2	3.922	1.297	11.863	<0.05
Smoking	1.029	0.364	2.913	n.s.
Hypertension	0.838	0.311	2.259	n.s.
Abnormal glucose tolerance	2.176	0.675	7.016	n.s.
Heart disease	1.149	0.304	4.345	n.s.
Collagen disease	1.181	0.199	7.018	n.s.
Malignant tumor surgery	2.860	1.083	7.522	<0.05
Blood transfusion	3.834	1.683	8.737	<0.01
IPC	0.396	0.193	0.814	<0.05

BMI: body mass index

CI: confidence interval

IPC: intermittent pneumatic compression

n.s.: not significant