DVT: it's now clear that flying puts us more at risk

DVT: it's now clear that flying puts us more at risk

Airlines have long argued that the cause of DVT is nothing more than a matter of sitting still - while in the same breath denying any link with cramped seating conditions or lack of legroom in the aircraft cabin. They have argued against use of the term "economy-class syndrome" (since cases also occur in business class), preferring to call it "traveller's thrombosis", on the basis that you can be just as immobile in a car or on a train.

This new study shows clearly and conclusively, however, that there really is something special about being in the air, beyond reduced mobility; that the risk varies from person to person, with some being at particular risk; and that DVT risk factors have a cumulative effect. The study looked at two possible risk factors, but there are many more, including pregnancy, HRT, previous blood clots, a history of cancer, recent surgery, being over 40, and being tall, short or overweight.

What is the overall risk of DVT? Symptomless clots that clear up and go away have been found in as many as one in 10 long-haul air travellers. The Department of Health estimates the rate of overt DVT to be one per 6,000 journeys. The death rate from pulmonary embolism, DVT's potentially lethal complication, is small (estimated at one per two million arriving international passengers in Australia).

These are not rates that will induce any of us to tear up our air tickets and stay at home, but they nonetheless have an important impact on fit, healthy air travellers, often in their prime.

Recent rulings in the Appeal Court and House of Lords have confirmed that, regardless of its cause, airlines cannot be liable under present legislation for injury or death from DVT and its complications. Secure in this knowledge, the airlines should now do much more to inform and protect their passengers. If they fail, they will justly invite much tighter regulation in future.