Effectiveness of Ambulation to Prevent Venous Thromboembolism in Patients Admitted to Hospital: a Systematic Review

Background: Patient ambulation is frequently recommended to help prevent venous thromboembolism during hospital admission. Our objective was to synthesize the evidence for ambulation as a prophylaxis for venous thromboembolism in hospital.

Methods: We conducted a systematic review. We searched MEDLINE, Embase, Scopus, Web of Science and Cochrane Central Register of Controlled Trials indexed from their inception through April 2020 for studies of adult patients admitted to hospital, in which ambulation or mobilization alone or concomitant with prophylaxis was indicated for prevention of venous thromboembolism. We searched ClinicalTrials.gov for unpublished trials. We included randomized controlled trials (RCTs) and observational studies. Two reviewers independently screened articles and assessed risk of bias using 2 validated tools. We scored studies on quality of reporting, internal and external validity and study power; combined scores determined the overall quality.

Results: Eighteen articles met the inclusion criteria: 8 retrospective and 2 prospective cohorts, 7 RCTs and 1 secondary analysis of an RCT. The intervention (ambulation or mobilized) groups varied across studies. Five studies examined exercise as a therapeutic prophylaxis for thrombosis and 9 described an ambulation protocol. Five studies attempted to quantify amount and duration of patient ambulation and 3 reported ambulation distance. In the 5 studies rated as good or excellent statistical quality, findings were mixed. Incidence of venous thromboembolism was lowest when pharmacologic anticoagulants were added as part of the prescribed prophylaxis regimen.

Interpretation: We did not find high-quality evidence supporting ambulation alone as an effective prophylaxis for venous thromboembolism. Ambulation should not be considered an adequate prophylaxis for venous thromboembolism, nor as an adequate reason to discontinue pharmacologic prophylaxis for venous thromboembolism during a patient's hospital admission.