Table 4.

Multivariate analysis using Cox logistic regression model to evaluate potential risk factors for the occurrence of VTE in patients receiving prophylactic LMWH or fondaparinux for thromboprophylaxis after major orthopaedic surgery (n= 3447)

	Patients with/without VTE
	HR	95% CI	P value
Use of fondaparinux	1.25	0.90, 1.75	0.184
Female gender	1.89	1.30, 2.75	0.001
Age (per year)	1.03	1.01, 1.04	<0.001
Platelet count	0.99	0.99, 1.00	0.024
Previous VTE	18.21	11.64, 28.48	<0.001
BMI (per unit)	1.05	1.02, 1.08	<0.001

HR = hazard ratio.