Deep vein thrombosis and air travel: record linkage study

Abstract

Objective To investigate the time relations between long haul air travel and venous thromboembolism. Design Record linkage study using the case crossover approach. Setting Western Australia. Participants 5408 patients admitted to hospital with venous thromboembolism and matched with data for arrivals of international flights during 1981-99. Results The risk of venous thromboembolism is increased for only two weeks after a long haul flight; 46 Australian citizens and 200 non-Australian citizens had an episode of venous thromboembolism during this so called hazard period. The relative risk during this period for Australian citizens was 4.17 (95% confidence interval, 2.94 to 5.40), with 76% of cases (n = 35) attributable to the preceding flight. A "healthy traveller" effect was observed, particularly for Australian citizens. Conclusions The annual risk of venous thromboembolism is increased by 12% if one long haul flight is taken yearly. The average risk of death from flight related venous thromboembolism is small compared with that from motor vehicle crashes and injuries at work. The individual risk of death from flight related venous thromboembolism for people with certain pre-existing medical conditions is, however, likely to be greater than the average risk of 1 per 2 million for passengers arriving from a flight. Airlines and health authorities should continue to advise passengers on how to minimise risk.

Activation of coagulation system during air travel: a crossover study

“…The results from studies suggest a 2-4-fold increased risk of thrombosis after air travel; [2][3][4] with a greater risk after longer flights than after shorter ones. 5,6 The mechanism of thrombus formation during air travel, however, is unclear.…”

Knowledge, Attitude and Perceptions of Indian long-distance Train Travellers Towards Medicinal Drugs, Healthcare, and Hygiene while Travelling: A Questionnaire-based Survey

“…6 Fourth, travelling in trains for several hours may lead to immobility and predispose travellers to deep vein thrombosis. 7,8 Fifth, several pre-existing cardiovascular, respiratory diseases could exacerbate due to the strain involved during long-distance travel. 8 Since drugs play a major role in alleviating the signs and symptoms of most of the medical conditions that passengers encounter during their train journeys, inadequate knowledge about them could decrease their preparedness before a journey, decrease their ability to counter anticipated travel-related illnesses, and decrease reporting of adverse drug events.…”

“…This collection of symptoms, also called as 'travel-fatigue' , is also common in travellers in other modes of transportation. [6][7][8][9][10][11][12][13] Although, a majority of the participants actively sought help in case they encountered a medical problem while travelling, a substantial number did not want to do anything about it till their journey ended. This indicated that knowledge about the healthcare facilities provided by the Indian Railways and the drugs used to treat minor health problems encountered by travellers while travelling is sparse; hence, policy makers must take steps to generate more awareness about these two issues.…”

Relation between Air Travel and Venous Thromboembolism

“…A descriptive study on the rate of occurrence of fatal PE estimated the rate at 0.5 per million and 1.3 per million occurring among travelers taking flights of more than 3 hours and more than 8 hours, respectively (58) . The time frame that was reported for development VTE after prolonged flight was estimated at between 2 and 8 weeks (40) . In four prospective studies conducted on the development of VTE following travel, objective methods of evaluation of VTE were used prior to and after traveling (36,37,73,74) .…”