The summary of results from an extensive research programme published y the UK Department for Transport confirms that long-distance travel leads to a small but increased risk of deep vein thrombosis (DVT). The risk, which applies to all forms of travel, appears to be predominantly the result of prolonged immobility.
Following the largest ever study of its kind, it was found that all forms of transport involving a journey of 4 hours or more led to an increase in the risk of blood clots forming in the veins of the legs.
And in a study of air passengers of working age, for example, one case of DVT was found for every 6000 journeys that lasted 4 hours or more.
However, such clots are far more common amongst those in hospital than in those who travel. Every year DVT occurs in about 1-3 per 1000 people in the general population, ranging from fewer than 1 in 3000 in people under the age of 40 up to 1 in 500 in those over 80.
In all incidences of DVT, travel related or otherwise, only 1% of cases prove to be fatal.
The project was funded by the Department for Transport, the Department of Health and the European Commission, and carried out by a consortium of medical research scientists under the auspices of the World Health Organisation.
Commenting on the results Transport Minister Karen Buck said:
“This important research project has shown that DVT can occur in any form of travel where people remain seated for a long time.
“Incidences of DVT are generally low, but long journeys were found to increase the risk by approximately three-fold, which is a level comparable to the risk of DVT faced by women during pregnancy.
“It has also confirmed our understanding of the categories of people who are at higher risk, such as older people, those with hereditary blood conditions, women using oral contraception, people on journeys of more than 12 hours and very tall people.
“Despite the rarity of these occurrences, I recommend that all travellers refer to the Department of Health’s advice.”
The Department of Health website offers advice on reducing the risk of DVT during journeys. Sitting still for long periods of time on long journeys - whether by plane, train, car or coach - can lead to DVT (a blood clot in the leg).
Department of Health advice is to move your feet around, or get up and walk around as regularly as you can.
It is also important to drink a reasonable amount of water or non-alcoholic drinks to avoid dehydration.
The advice is available at: www.dh.gov.uk/PolicyAndGuidance/HealthAndSocialCareTopics/BloodSafety/VT E/fs/en and www.dh.gov.uk/VTE