While there is a lot of conjecture regarding the risk of DVT and pulmonary embolism from air travel, there is remarkably little scientific evidence to quantify what the level of risk might be or if there even is an association between air travel and DVT.

The British government has recently commented on the the lack of data on DVT and air flight. At issue is if the number of persons developing DVT after flying is markedly higher than the number expected to develop DVT (without exposure to flying). The WHO, and the British, and Australian governments have called for new studies in this area.

See: House of Lords, Select Committee on Science and Technology Fifth Report. (at WEB)