The condition has been linked to long-haul flights and dubbed "Y class syndrome" because passengers travelling in economy or Y class on airliners often do not have the space to stretch enough to reduce the risk of blood clotting.
 
The study's lead author, Richard Beasley, told National Radio on Monday: "Being seated for long periods of time ... the risk is certainly there.
 
"There are considerably more people who are seated for long periods at work as part of their normal day than there are travelling,'' he said, adding that the main groups affected were workers in the information technology industry and in call centres.
 
The study covered 62 patients aged under 65 who were admitted to hospital with blood clots.
 
Long hours
 
Beasley said a surprise finding of the study was that people were working very long hours.
 
"We had people not uncommonly working up to 12-14 hours a day and being seated for that time"

Richard Beasley, study's lead author
"We had people not uncommonly working up to 12-14 hours a day and being seated for that time."
 
The 34 per cent finding is far higher than the 1.4 per cent of blood-clot patients who recently travelled on long-haul flights, and the study showed a clear link between travel and work-related thrombosis.
 
"It's the same thing occurring in a similar circumstance as travellers' thrombosis,'' he noted.
 
Some reported being seated on the job for 3-4 hours at a time, "reflecting the very sedentary nature of our work at the moment", he said.
 
The study is set to be published next month in the New Zealand Medical Journal.