Rationale supporting an "opt-out" policy for pharmacological venous thromboembolism prophylaxis in hospitalized medical patients.

Pulmonary embolism is the number one cause of preventable death among hospitalized patients. Prescription of either low dose low molecular weight heparin, such as enoxaparin or dalteparin, or prescription of low dose fondaparinux can halve the rate of deep vein thrombosis or pulmonary embolism, without increasing major bleeding complications. Nevertheless, there has been a "failure-to-prophylax" syndrome, especially among hospitalized medical patients at risk. One approach is to mandate venous thromboembolism prophylaxis for these patients without exception or flexibility. The alternative approach is to institute or maintain an "opt-out" policy so that the responsible clinician can make the final decision as to whether the benefits of prophylaxis outweigh the risks. This paper, makes the case for an "opt-out" policy, so that we can personalize, individualize, and humanize our medical care. Such an approach permits flexibility, encourages collaborative "buy-in" to the concept of prophylaxis, and allows the clinician to withhold anticoagulation in special situations that do not fit prespecified protocols. Ultimately, such an "opt-out" policy might make VTE prophylaxis more effective by avoiding anticoagulation of low thrombosis risk patients who are at high risk of bleeding complications.