Table 2:

Results of included studies of ambulation to prevent venous thromboembolism

Study	Ambulatory group description	Ambulation quantified?	Comparison group description	Pharmacological VTE prophylaxis	Outcome (definition)	Group sizes	Results		Study conclusion
Miller et al (39)	Sitting and standing at the bedside for 30 min 3 times/d; ate meals while sitting	No	Five days of bed rest with leg exercises hourly	No	DVT (¹²⁵I-fibrinogen)	21	Amb	10%	Early mobilization program reduces the incidence of venous thrombosis in acute MI
Miller et al (39)		No	Five days of bed rest with leg exercises hourly	No	DVT (¹²⁵I-fibrinogen)	8	Control	63%

Prerovský et al (40)	Dorsal and plantar flexion for 1–2 min every hour while awake	No	Standard of care without chemical VTE prophylaxis	No^*	DVT (¹²⁵I-fibrinogen)	135	Amb	5.2%	Moderate lower limb exercise is the simplest measure to prevent VTE
						133	Heparin	9.0%
						140	Control	13.6%

Vioreanu et al (41)	Custom made removable fiberglass cast with ankle exercises 3 times/d for 10 min	No	Non-removable fiberglass cast for 6 weeks	NR	VTE	29	Amb	0%	Postoperative immobilization may increase DVT risk
Vioreanu et al (41)		No	Non-removable fiberglass cast for 6 weeks	NR	Clinical	33	Control	6%	Postoperative immobilization may increase DVT risk

Sorbello et al (42)	Sitting or standing within 24 h for 6 d with aid of nurse or physiotherapist	No	Standard of care	NR	VTE (NR)	33	Amb	0%	No difference in complications after initiation of early mobilization
Sorbello et al (42)		No	Standard of care	NR	VTE (NR)	38	Control	0%

Amin et al (46)	Ability to attain autonomous walking distance > 10 m	Yes	Did not attain autonomous walking > 10 m	Yes^†	VTE (clinical)	607	Amb	8.4%^‡	In the prevention of VTE, reaching ambulatory status may not be a reason for stopping pharmacological prophylaxis
Amin et al (46)	Ability to attain autonomous walking distance > 10 m	Yes	Did not attain autonomous walking > 10 m	Yes^†	VTE (clinical)	447	Control	16.2%

Wang et al (43)	Dorsal and plantar flexion 30 times/min, 20 times/d in first 7 postoperative days	No	Standard of care	NR	DVT (doppler or clinical)	78	Amb	7.6%	Significant reduction in all DVTs but no difference in symptomatic DVTs (2.2% v. 3.9%)
Wang et al (43)		No	Standard of care	NR	DVT (doppler or clinical)	96	Control	18.4%

de Almeida et al (44)	Twice daily exercise program based on patient’s functional ability	Yes	Once daily exercise program	NR	DVT (clinical)	54	Amb	1.8%	Primary outcome was ability to walk but no difference in DVT
de Almeida et al (44)		Yes	Once daily exercise program	NR	DVT (clinical)	54	Control	0%

Guo et al (45)	Active ankle motions, calf massage and deep breathing	No	Standard of care	Yes	DVT (clinical or ultrasonography)	53	Amb	1.9%	Because of the sample size limitation, the authors could not draw any conclusion about the effects of exercise on the prevention of VTE
Guo et al (45)	Active ankle motions, calf massage and deep breathing	No	Standard of care	Yes	DVT (clinical or ultrasonography)	62	Control	1.6%

Lassen and Borris (29)	Mobilized from postoperative day 4 onward	No	Mobilized from postoperative day 9 onward	Yes	DVT (phlebography)	35	Amb	21%	Patients may lose benefit of pharmacological VTE prophylaxis if they are not mobilized
Lassen and Borris (29)	Mobilized from postoperative day 4 onward	No	Mobilized from postoperative day 9 onward	Yes	DVT (phlebography)	35	Control	75%

Karic et al (30)	Progressive mobilization from HOB elevation to sitting, standing and walking to restroom	No	Standard of care	Yes	VTE (clinical)	77	Amb	4.2%	No impact on VTE but reduced postoperative vasospasm
Karic et al (30)		No	Standard of care	Yes	VTE (clinical)	94	Control	3.8%	No impact on VTE but reduced postoperative vasospasm

Moses (32)	Forced respirations and 2-min bicycle exercise every day or twice daily while awake	No	Standard of care	NR	VTE (clinical)	74	Amb	0%	Bicycle or deep breathing reduce thrombotic complications
Moses (32)		No	Standard of care	NR	VTE (clinical)	74	Control	5%	Bicycle or deep breathing reduce thrombotic complications

Flanc et al (33)	Supervised exercise 6 times/d with nursing reminders to exercise	No	Standard of care	NR	DVT (¹²⁵I-fibrinogen)	65	Amb	25%	Strain on hospital resources and only benefit was in older patients
Flanc et al (33)		No	Standard of care	NR	DVT (¹²⁵I-fibrinogen)	67	Control	35%

Pearse et al (34)	VTE prevention protocol including < 24 h mobilization	No	Routine ambulation on POD #2	Yes	DVT (Doppler)	97	Amb	1%	Early mobilization reduces radiographic DVT
Pearse et al (34)	VTE prevention protocol including < 24 h mobilization	No	Routine ambulation on POD #2	Yes	DVT (Doppler)	98	Control	28%	Early mobilization reduces radiographic DVT

Chandrasekaran et al (35)	Mobilized with first 24 h, at least twice daily, 15–30 min, by physiotherapists	Yes (sitting, 1–5 m, > 5 m)	Routine out of bed to chair and walking POD #2	Yes	VTE (Doppler or clinical)	50	Amb	16%	Early mobilization reduces postoperative DVT, particularly if > 5 m (no VTE in 15 patients)
Chandrasekaran et al (35)		Yes (sitting, 1–5 m, > 5 m)	Routine out of bed to chair and walking POD #2	Yes	VTE (Doppler or clinical)	50	Control	38%

Frantzides et al (36)	VTE prevention protocol including ambulation within 2 h	No	Standard of care with enoxaparin	Yes (control only)	VTE (NR)	1257	Amb	0.5%	Early ambulation as part of a comprehensive protocol obviates need for pharmacological prophylaxis except in high-risk patients
Frantzides et al (36)	VTE prevention protocol including ambulation within 2 h	No	Standard of care with enoxaparin	Yes (control only)	VTE (NR)	435	Control	2.7%

Cassidy et al (37)	New comprehensive VTE prevention protocol including mobilization 3 times/d	No	Prior to protocol with no predefined practice	Yes (according to risk assessment)	VTE (NSQIP)	1569	Amb	3%	Postoperative mobilization program, risk stratification and electronic recommendations reduce VTE
Cassidy et al (37)		No	Prior to protocol with no predefined practice	Yes (according to risk assessment)	VTE (NSQIP)	1323	Control	0.8%

Bhatt et al (31)	Twice daily exercise program with pedal exerciser or POD#2 or when able to sit	Yes	Standard of care	NR	VTE (clinical)	30	Amb	0%	No impact on VTE but reduced infectious complications postoperatively
Bhatt et al (31)		Yes	Standard of care	NR	VTE (clinical)	30	Control	0%

Silver et al (38)	Bedrest for = 24 h	No	At least 12 h of bedrest	No	DVT (clinical)	203	Amb	0.5%	No effect on VTE but reduction in pneumonia and LOS
Silver et al (38)	Bedrest for = 24 h	No	At least 12 h of bedrest	No	DVT (clinical)	189	Control	1.5%	No effect on VTE but reduction in pneumonia and LOS

Note: Amb = ambulation, DVT = deep vein thrombosis, HOB = head of bed, LOS = length of stay, MI = myocardial infarction, NR = not reported, NSQIP = National Surgical Quality Improvement Program, POD = postoperative day, RCT = randomized controlled trial, VTE = venous thromboembolism.
↵* Ambulation and Enoxaparin 40 mg once daily had the lowest rate of VTE at 3.3%.
↵† Heparin was used in a third group but not ambulatory or control group.
↵‡ Patients in both groups were randomly assigned to receive placebo, enoxaparin 40 mg or 20 mg once daily.