Objectives: To assess the benefits in terms of reductions in the risks of deep vein thrombosis (DVT) and of pulmonary embolism (PE), and hazards in terms of major bleeding, of: (i) mechanical compression; (ii) oral anticoagulants; (iii) dextran;. and (iv) regional anaesthesia (as an alternative to general anaesthesia) in surgical and medical patients. Data sources: Electronic databases, search of Antithrombotic Trialists' Collaboration database, contact with trialists and manufacturers. Revie...