Table 4.

Linear models’ coefficient rank

All variables
Top 10 (median)	Top 10 (mean)
Any VTE 12 months prior to surgery	Any VTE 12 months prior to surgery
Surgery time (min)	Surgery time (min)
Utilization of any chemoprophylaxis weeks/in 30 days (coded)	Utilization of any chemoprophylaxis weeks/in 30 days (coded)
Timing of heparin (days)	Timing of heparin (days)
Stage II surgery time	Timing of onset of any anticoagulant
EBL	Total anesthesia time (included all stages)
Enoxaparin first dose	EBL
Total anesthesia time (included all stages)	Stage III surgery start
DVT 12 months prior to surgery	Anesthesia length (min)
Diabetes	Enoxaparin first dose
Preoperative variables only
Top 10 (median)	Top 10 (mean)
Age	Thoracic
DVT 12 months prior to surgery	DVT 12 months prior to surgery
PE 12 months prior to surgery	PE 12 months prior to surgery
Any VTE 12 months prior to surgery	Department
BMI	Any VTE 12 months prior to surgery
Staged	Foraminotomy
Cyst/abscess	BMI
Anterior	Fusion
Smoking status	Gender
Fusion	Endoscopic

VTE - Venous thromboembolic event; EBL - Estimated blood loss; DVT - Deep venous thrombosis; PE - Pulmonary embolism; BMI - Body mass index