Venous thrombosis affects more than 30,000 Australians each year and is responsible for over 5000 deaths per annum, this is more than the number of Australians who die from motor vehicle accidents annually. VTE is the third leading cause of death amongst hospitalised patients and patients admitted to hospital are at least 100 times more likely of developing a clot compared to being active in the community-a risk that may be assessed by the modified Wells criteria.