Table 1

Characteristics of the included studies.

Study	Study Design	No. of Patients	Age, y, median	Period	VTE Prophylaxis Timing Definition		Inclusion Criteria of Study
Study	Study Design	No. of Patients	Age, y, median	Period	Early	Late	Inclusion Criteria of Study
Hamidi, 20209	Retrospective cohort analysis	526	46 ± 22 y	2014–2017	≤48 h	>48 h	Adult patients (≥18 y old) with trauma with any isolated spinal trauma (extraspinal abbreviated injury scale <3) who were managed operatively and received chemical thromboprophylaxis with LMWH.
Zeeshan, 201810	Retrospective clinical trial	3554	34.8 ± 20.9	2013–2014	<48 h	>48 h	Adult patients (>18 y old) with isolated spine injury and diagnosed vertebral fracture who received LMWH and underwent operative intervention.
Aito, 200211	Prospective clinical trial	275	Early: 41.3 Late: 42.3	1 January 1996 to 15 May 2000	Within 72 h	7–28 d postinjury (mean 12 d)	All acute traumatic BSI patients consecutively admitted with motor complete and incomplete lesions. Absence of contraindications to heparin and/or mechanical prophylaxis.