Table 6

Multivariable ORs for VTE, controlling for demographic and operative variables

Variables	OR	95% CI	P value*
Age, years
≤1	0.992	0.715 to 1.376	0.961
2–5	1.074	0.761 to 1.516	0.683
6–10	0.625	0.414 to 0.940	0.024
11–15	Referent
16–18	1.892	1.374 to 2.606	<0.001
Sex
Female	Referent
Male	0.977	0.797 to 1.199	0.827
ASA class
I	Referent
II	4.502	2.317 to 8.745	<0.001
III	19.715	10.316 to 37.677	<0.001
IV	71.17	36.339 to 139.386	<0.001
V	154.953	62.838 to 382.097	<0.001
Surgical specialty
Cardiothoracic surgery	3.248	1.293 to 8.156	0.012
Gynecology	1.992	0.484 to 8.197	0.34
General surgery	Referent
Neurosurgery	0.622	0.463 to 0.837	0.002
Orthopedic surgery	0.496	0.341 to 0.704	<0.001
Otolaryngology (ENT)	0.465	0.288 to 0.749	0.002
Urology	0.31	0.162 to 0.594	<0.001
Plastic surgery	0.141	0.045 to 0.443	0.001
Non-elective surgery	1.678	1.332 to 2.114	<0.001
Operative time (min)	1.004	1.003 to 1.004	<0.001

*Logistic regression including all variables listed in this table. Bolding indicates statistical significance at p<0.05.
ASA, American Society of Anesthesiologists; CI, confidence interval; ENT, ear, nose and throat; OR, odds ratio; VTE, venous thromboembolism.