Panic: ‘Workers who sit in front of a computer for hours at a time are more at risk from deadly blood clots than frequent flyers’ says the Daily Mail, reporting on a study conducted by the privately-funded Medical Research Institute in New Zealand (1). Researchers looked into cases of deep vein thrombosis (DVT) in 62 patients, aged up to 65, who were admitted to hospital with blood clots. The survey found that 34 per cent had been ‘seated at work for long periods’.

The risk of DVT to airline passengers became a widespread panic in 2000, after several healthy travellers died after long haul flights. During the flights, the patients who died from DVT would have been immobile for a long period - with cramped legs, and restricted circulation.  Blood clots can then form in the deep veins of the legs. In turn, the blood clot can then travel up from the legs to block a lung artery, a phenomenon known as a pulmonary embolism. Where the clots are large or numerous, they can lead to death. Now it looks like high-risk individuals could be told to take extra special care at their desks, too.

Don’t panic:The panic over DVT, which exploded late in 2000, was due, not to a report on the phenomenon but after 28-year-old UK resident Emma Christoffersen tragically collapsed and died after a 20-hour flight from Australia in October 2000 (2). Her story captured the public imagination: she was young, healthy and just about to get married. As her fiancé Tim Stuart put it, ‘[DVT] seems to strike at random, and in a way it’s just like Russian roulette. It could happen to anyone.’ (3)

In fact, the number of cases specifically caused by flights was always very low or even non-existent. As Josie Appleton notes elsewhere on spiked ‘some scientists have found evidence for a link between flying and DVT - others have found evidence indicating that there is no link. And both sets of evidence are disputed. But the scientists do agree on one thing: if there is an increased risk of DVT caused by flying, it is small and mainly affects individuals who are already predisposed to DVT - such as people who have had recent surgery, have blood clotting disorders, or are pregnant.’ (See DVT: Anatomy of panic by Josie Appleton).

The New Zealand study is small and it is not clear how the proportion of people who had been ‘sitting for a long time’ compared with the proportion of people with desk jobs in the general population. The claim by the researchers working on the study that blood clots from desk jobs are a new form of deep vein thrombosis, so-called ‘e-thrombosis’, because of the increasing trend for sedentary jobs and longer working hours, seems questionable. In the UK, such working conditions have been the norm for at least the last 20 years.

So far we do not have a single case of a UK office worker dropping dead at work after suffering from ‘e-thrombosis’. If there were any reason at all to panic - we’d know about it by now. Still, it can’t be long before the health and safety people demand that we do a jig every couple of hours to keep the blood moving.

(1) See Computer staff ‘at greater risk of DVT than flyers’, Daily Mail, 12 March 2007

(2) See Blood clot kills woman after flight, Guardian, 23 October, 2000

(3) Perils of cheap flights may force up prices, Guardian, 23 November 2001