In contrast to surgical patients, the prevention of DVT in the general medical patient has been less well studied. Nevertheless, there are smaller studies on specific subpopulations that allow making a recommendation about prophylaxis for the many nonsurgical patients.
The incidence of DVT in untreated medical patients varies form 16% to 55% with the latter occurring in patients suffering from ischemic stroke. The relative risk reduction in patients undergoing treatment has been shown to be between 61 to71% for low dose unfractionated heparin and 58 to 76% with low molecular weight heparins.