Impact of venography on the diagnosis and management of deep vein thrombosis.

In general medical patients presenting with suspected deep vein thrombosis routine use of x ray venography was associated with a large fall in the proportion of patients with a final diagnosis of deep vein thrombosis, from 83% to 25% (p less than 0.001), and with an appreciable shortening of hospital stay, from 13.6 to 7.2 days. The diagnosis of deep vein thrombosis was rejected in only 4% of patients when a venogram was not performed, and it is estimated that two patients were treated with anticoagulants unnecessarily for every patient treated correctly. The risk, expense, and inconvenience of unnecessary anticoagulant treatment far exceeds the risk, expense, and inconvenience of performing venograms routinely. The common practice of misdiagnosing deep vein thrombosis clinically should be abandoned.