The incidence of venous thromboembolism in low to moderate risk long distance air travellers: The NZATT study
This is the largest prospective study ever undertaken of the incidence of venous thromboembolism (blood clots) in long distance travellers. One thousand subjects were recruited with all subjects travelling for at least 10 hours with a mean duration of air travel of 39 hours. The incidence of blood clots associated with travel was 1.0%. Six of the subjects with blood clots had pre-existing clinical risk factors, two travelled exclusively in business class, six used aspirin and four wore compression stockings.
These results, which were published in The Lancet, confirmed that an association between travel involving multiple long distance air flights and blood clots exists, even in low to moderate risk individuals. They also suggested that the role of traditional risk factors and prophylactic measures in air traveller's thrombosis requires further investigation.