A study was announced on March 17 that could turn “economy class syndrome” – the common tag for deep vein thrombosis (DVT) – into “deskbound syndrome.” By either name DVT is a blood clot in a deep vein of the legs, pelvis, chest or arms. It was a well-timed announcement – March is Deep Vein Thrombosis Awareness Month, and DVT was already in the news because Vice President Dick Cheney was diagnosed with it on March 4.

Prolonged sitting has been linked to DVT since World War II. It picked up its “economy class” tag in 1988 in a paper published in The Lancet by researchers JM Cruikshank et al. Paradoxically, one of the victims cited in the study traveled in business class. The researchers concluded that budget travelers, particularly on long-haul flights, were at particular risk for the condition. Tight seats and scant legroom were presumed to prevent opportunities to move about to aid circulation. Though several influential studies have since challenged the importance of economy class travel as a risk factor, the expression has stuck.

The new study demotes flying in any class as a major risk factor, conferring that distinction on office work in certain circumstances. The March issue of The Ergonomics Report™, a publication for subscribers in ergonomics-related professions, traced the history of “economy class syndrome” so the drama of the latest demotion can be appreciated.

Professor Richard Beasley of New Zealand's privately funded Medical Research Institute found that workers glued to computer screens are at greater risk of blood clots forming in their legs than long-distance air travelers. The announcement was picked up by the news services and the study will be published in April 2007 in the New Zealand Medical Journal.

His team’s study covered 62 patients under 65 years old who were admitted to hospital with blood clots. It found that 34 percent – a far higher figure than the range reported for airline-related DVT – of patients admitted to hospital with the problem had been seated at work for long periods. "There are considerably more people who are seated for long periods at work as part of their normal day than there are traveling," said Dr. Beasley in an Associated Press (AP) article about the announcement, adding the main groups affected are workers in the information technology industry and in call centers.

He also said he was surprised to find "people are working for so long. We had people not uncommonly working up to 12-14 hours a day and being seated for that time."

Dr. Beasley and his team reported preliminary findings linking DVT with long hours at the computer in 2003 in a paper published in the European Respiratory Journal. The follow-up study, which will be published in April in the New Zealand Medical Journal, supports the earlier findings.

The study is well timed for the Coalition to Prevent Deep-Vein Thrombosis, which sponsored the March awareness month. The Coalition aims to educate the public about the condition. Up to 600,000 Americans are hospitalized each year for DVT and its primary complication, according to a Coalition news release, and up to 300,000 die of its complications. Despite the grim statistics, a recent survey by the organization revealed that most Americans – 60 percent – do not know about the problem.

The Vice-President’s clot, a headline story, played a significant role in raising awareness of DVT. His doctors said the DVT is due to his long-present circulatory problems, in combination with his recent 25,000 mile flight to Australia, Afghanistan and Pakistan.

The readiness to blame air travel is an indication that “economy class syndrome” is dying hard. It appears Professor Beasley and his team have work ahead of them to convince the world that DVT is more of a problem for deskbound people. Sources: The Ergonomics Report™; Associated Press