Venous thromboembolism in hospitalized patients: an updated analysis of missed opportunities for thromboprophylaxis at a university-affiliated tertiary care center.

Thromboprophylaxis remains often underused in hospitalized patients. In 2001, a cohort study done at our institution, a tertiary care center in Montreal, Canada, showed that 67.7% of VTE cases necessitating thromboprophylaxis were potentially preventable with adequate use of American College of Chest Physicians (ACCP) guidelines. Following implementation of an institution-wide policy in 2005, we assessed the changes in the rate of potentially preventable VTE. We conducted a retrospective cohort study including all hospitalized patients with objectively diagnosed VTE in 2010 at our institution. Each case was classified as preventable (thromboprophylaxis indicated but inadequately administered), non-preventable (thromboprophylaxis indicated and correctly administered), spontaneous (thromboprophylaxis not indicated), and ineligible (contraindication to thromboprophylaxis). The results were compared to those obtained in 2001. Of the 230 cases of VTE, 55 cases were classified as potentially preventable (23.9%), 85 were non-preventable (37.0%), 74 were spontaneous (32.2%) and 16 (7.0%) were ineligible. Of the 140 cases requiring thromboprophylaxis, 39.3% were potentially preventable. The potentially preventable cases were mostly due to omission of thromboprophylaxis (50.9%), occurred during general medical admissions (74.5%), and the most common VTE risk factor was cancer (47.2%). In conclusion, we demonstrate a lower frequency of potentially preventable cases in 2010 compared to 2001 (39.3% vs 67.7%, respectively), partially due to physician education and adoption of an institution-wide policy. However, patients with medical indications for thromboprophylaxis, particularly those with cancer, are more prone to having preventable VTE, indicating an area for potential improvement.