Toronto Thromboprophylaxis Patient Safety Initiative

Overview

Venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE, is one of the common and preventable complications of hospital stay. VTE prophylaxis through the use of evidence-based anticoagulant medication options or mechanical prophylaxis have been shown to reduce this risk and improve patient safety. Despite an abundance of evidence, use of VTE prophylaxis remains low. This study assesses the effectiveness of quality improvement strategies (use of pre-printed orders, audit and feedback, involvement of the pharmacist as project need and as a reminder to the physician, and education of staff) on use of appropriate VTE prophylaxis. The study aims to measure if the use of these strategies improves the use of VTE prophylaxis and therefore, improves patient safety and patient care by reducing the risk of developing DVT or PE.

The study includes 8 Toronto area hospitals consisting of 7 community hospital and one academic health sciences centre. Three patient groups at each site are included in the study: patients admitted for: Acute Medical Illness (AMI), Major General Surgery (MGS) and Hip Fracture Surgery (HFS). Patients had to be at least 18 years old and be considered at risk for VTE according to the American College of Chest Physicians (CHEST) guidelines. The study design is a cluster randomized trial where each patient group at each site is a cluster. A baseline chart audit of approximately 50 patients in each group at each site was conducted to determine an intraclass coefficient and proportion of adherence. The main outcome measure was the rate of prescribing appropriate prophylaxis in patients at risk. This was calculated as the number of at risk patients receiving appropriate prophylaxis / the number of at risk patients for whom prophylaxis is indicated. Based on the baseline results, it was estimated that a sample size of 432 would be needed for the intervention phases. A sample of 720 patients (15 in each cluster at each site) was included. The study is broken down into three phases: baseline, phase 1 and phase 2. At baseline, all groups received usual care. At phase 1, one cluster at each site was randomized to intervention while the other two served as control. In phase 2, 2 groups received intervention while one continued to serve as control. Each of the phases, phase 1 and 2 had 360 unique patients. Patients in baseline were not included in phase 1 or 2 and patients in phase 1 were not included in phase 2. The main outcome measure was prescribing of appropriate VTE prophylaxis. A chart audit was used to collect data at baseline, end of phase 1 and end of phase 2. Each phase is approximately 1 year in length. Analysis involves descriptive statistics using counts and proportions to capture rates of appropriate VTE prophylaxis and rates of non-adherence. A logistic regression model will be used to compare rates of appropriate VTE prophylaxis over time within groups adjusted for clustering.