Venous Thromboembolism Prophylaxis on General Internal Medicine Units: Are Patients Well Served by Current Practice?

BACKGROUND: Venous thromboembolism (VTE) is the most preventable hospital-associated complication, and implementation of appropriate VTE prophylaxis is a requirement for institutional accreditation. However, ambiguity and controversy exist within current recommendations, and greater clarity about and understanding of current utilization of VTE prophylaxis may be needed.

OBJECTIVES: The primary objective was to assess the proportion of patients receiving appropriate VTE prophylaxis (right drug, dose, frequency, and duration) within 24 h after admission to general internal medicine units. The secondary objectives were to determine the proportion of at-risk patients who experienced adverse events (major bleeding or thrombotic events) in relation to appropriateness of prophylaxis, to describe reasons why VTE prophylaxis was inappropriate, and to compare these findings with local audit data.

METHODS: This cross-sectional study involved adult patients at moderate to very high risk of VTE who were discharged from general internal medicine units between January 1 and September 30, 2015, at the University of Alberta Hospital in Edmonton, Alberta. Patients with length of stay less than 72 h, those already receiving therapeutic anticoagulation, and those lacking documentation of renal function or weight were excluded. A paired t test was used to compare the study data with audit results.

RESULTS: Of 225 patients identified as being at risk of VTE, 179 (79.6%) received appropriate prophylaxis. The most common reasons why VTE prophylaxis was deemed inappropriate were not providing a mechanical method of prophylaxis for patients with bleeding contraindications (18/46 [39.1%]) and incorrect dose of pharmacologic prophylaxis (15/46 [32.6%]). The rate of appropriate VTE prophylaxis was lower than that reported in local audits (79.6% versus 97.6%; p = 0.002). Adverse events were less frequent among those receiving appropriate VTE prophylaxis than among those receiving inappropriate prophylaxis: 1.7% (3/179) versus 6.5% (3/46) for thrombotic events and 4.5% (8/179) versus 19.6% (9/46) for major bleeding.

CONCLUSIONS: These results provide insight into current prescribing patterns for VTE prophylaxis and highlight the need for continued engagement of the health care team in the provision of appropriate VTE prophylaxis.