Multicenter evaluation of the use of venous thromboembolism prophylaxis in acutely ill medical patients in Canada

Abstract

Background: Venous thromboembolism (VTE) prophylaxis in acutely ill medical patients has been shown to be safe and effective. Underutilization of this patient safety practice may result in avoidable mortality and morbidity.

Objectives: We aimed to determine the proportion of hospitalized, acutely ill medical patients across Canada who were eligible to receive thromboprophylaxis and to evaluate the frequency, determinants and appropriateness of its use.

Patients/methods: CURVE is a national, multicenter chart audit of 29 Canadian hospitals. Data were collected on consecutive patients admitted to hospital for an acute medical illness during a defined 3-week study period. Information on demographic and clinical characteristics, risk factors for VTE and bleeding and use of VTE prophylaxis were recorded. The indications for and appropriateness of VTE prophylaxis were assessed using pre-specified criteria based on international consensus guidelines. Multivariable analyses were performed to identify determinants of prophylaxis use.

Results: Of the 4124 medical admissions screened over the study period, 1894 patients (46%) were eligible for study inclusion. The most common specified admitting diagnoses were severe infection (28%), COPD exacerbation or respiratory failure (12%), malignancy (9%) and congestive heart failure (8%). Thromboprophylaxis was indicated in 1702 (90%) study patients. Overall, some form of prophylaxis was administered to 23% of all patients. However, only 16% received appropriate thromboprophylaxis. Factors independently associated with greater use of prophylaxis included internist (vs. other specialty) as attending physician (OR 1.33, 95% confidence interval (CI) [1.03, 1.71]), university-associated (vs. community) hospital (OR 1.46, 95% CI [1.03, 2.07]), immobilization (per day) (OR 1.60, 95% CI [1.45, 1.77]), presence of >or=1 VTE risk factors (OR=1.78, 95% CI [1.35, 2.34]) and duration of hospitalization (per day of stay) (OR 1.05, 95% CI [1.03, 1.07]), however, use of prophylaxis was unacceptably low in all groups. Patients with cancer had a significantly reduced likelihood of receiving prophylaxis (OR=0.40, 95% CI [0.24, 0.68]). Presence of risk factors for bleeding did not influence the use or choice of prophylaxis.

Conclusion: Most patients hospitalized for medical illness had indications for thromboprophylaxis, yet only 16% received appropriate prophylaxis. Efforts should be made to elucidate the reasons that underlie the very low rate of thromboprophylaxis in medical patients and to develop and test strategies to improve implementation of this patient safety practice.