Following is a link to a survey conducted by the Orthopaedic Research and Education Foundation (OREF), on the topic: “Standards of Care in DVT Prophylaxis.” The results reveal no “standard of care;” rather, DVT prophylaxis is all over the map. OREF asserts: “Published clinical results with DVT therapies, safety and efficacy of DVT regimens, past experience with DVT therapies, patient characteristics and practice protocols most guide [sic] surgeons’ DVT decisions.”

However, a shrewd surgeon who understands pharmaceutical marketing has suggested a better explanation for how most surgeons decide on a protocol: "Dinners with good quality wines, coupled with presentation of drugs for DVT prophylaxis, make lasting impressions in surgeons' minds."

http://www.oref.org/DVT/results.html