Table 3

Categorical perioperative factors in patients with and without postoperative VTE

Operative variable	Total		No VTE		VTE		P value*
	n=361 384		n=361 006 (99.90%)		n=378 (0.10%)
	n	%	n	%	n	%
Surgical specialty							<0.001
Cardiothoracic surgery	426	0.12	421	0.12	5	1.32
Gynecology	848	0.23	846	0.23	2	0.53
General surgery	137 181	37.96	136 950	37.94	231	61.11
Neurosurgery	34 043	9.42	33 983	9.41	60	15.87
Orthopedic surgery	69 605	19.26	69 557	19.27	48	12.70
Otolaryngology (ENT)	45 226	12.51	45 207	12.52	19	5.03
Urology	40 800	11.29	40 790	11.30	10	2.65
Plastic surgery	33 255	9.20	33 252	9.21	3	0.79
Non-elective surgery	96 306	26.65	96 162	26.64	144	38.10	<0.001

*χ² test comparing patients with and without VTE. Bolding indicates statistical significance at p<0.025 (Bonferroni correction for multiple comparisons).
ENT, ear, nose and throat; VTE, venous thromboembolism.