The preventive use of blood thinners for four to six weeks after a hospital discharge reduces blood clot risks, according to a University of Alabama at Birmingham meta-analysis.

While most patients with acute medical illness are treated with prophylactic blood thinners, an increased risk of clotting remains for up to six weeks after discharge. The UAB study, published in the Public Library of Science, found that extending the duration of blood thinners in a patient’s post-discharge period continued to prevent blood clots, including fatal ones.

The researchers issued a note of caution, however. Extending the use of blood thinners also raises the bleeding risk. Based on the study results, they estimated that one in 350 patients treated in this way would have a bleeding event. 

“Careful selection of patients by the physicians is needed to optimally select patients for whom the benefits outweigh the risks,” said lead author Navkaranbir S. Bajaj, M.D.

Bajaj and colleagues analyzed five clinical trials of more than 40,000 patients, who were admitted for medical illness rather than surgery.

Read the study