Use of preventive measures for air travel-related venous thrombosis in professionals who attend medical conferences
Kuipers S, Cannegieter SC, Middeldorp S, Rosendaal FR, Buller HR. Use of preventive measures for air travel-related venous thrombosis in professionals who attend medical conferences. J Thromb Haemost 2006;4:2373-2376.
ABSTRACT: BACKGROUND: Lack of guidelines for prevention of air travel-related venous thrombosis may lead to excessive use of potentially dangerous precautions. OBJECTIVES: To assess the use of preventive measures for air travel-related thrombosis in professionals employed in the field of thrombosis and hemostasis and in other fields. Methods: A survey amongst delegates of the XXth ISTH Congress, the 15th ISDB Congress and the 13th Cochrane Colloquium, which all took place in Australia 2005. RESULTS: Two thousand and eighty-nine questionnaires were completed (response 53%). Overall, 80% of the respondents had used preventive measures. Low-molecular-weight heparin and vitamin K antagonists were mostly used by ISTH delegates (10% vs. 1% at the other conferences). Medical doctors used more pharmacological prophylaxis (31%) than research fellows (11%) and non-clinical scientists (22%). Dutch (64%) and Asian respondents (67%) least used any prevention, whereas Israeli used most (94%). Subjects with risk factors for thrombosis more often used prophylaxis (90%) than those without (77%). In a multivariate analysis, conference, nationality, age, presence of risk factors and profession were determinants of prophylaxis use. CONCLUSION: Major differences in the use of prophylactic measures for air travel-related thrombosis stress the need for studies of interventions and clear guidelines on prevention of air travel-related venous thrombosis.
Air Travel-related Venous Thrombosis – The Debate Continues
Review by Chiara Piovella, MD
In this observational study, the authors report a recent survey comparing travel-related thrombosis prophylaxis methods in attendees of three international conferences held last August in Sydney (the XXth ISTH Congress, the 15th ISDB Congress, and the 13th Cochrane Colloquium). The analysis revealed that ISTH delegates used prophylactic measures more often than others, and that medical doctors used LMWH prophylaxis more often than other ISTH delegates.
The most common risk factors were found to be estrogen use, varicose veins, thrombophilia and history of VTE. 49% of the individuals with prior VTE used anticoagulation pharmacoprophylaxis (33% LMWH and 16% warfarin) compared to 23% of the individuals without risk factors. Anticoagulation prophylaxis was also used by 40% of attendees with thrombophilia. In contrast, only 5% of hormonal therapy users and 15% of those with varicose veins used anticoagulant prophylaxis. Moreover, only 36% of passengers with varicose veins used elastic stockings.
In general, travelers with risk factors used anticoagulation and graduated compression stockings significantly more often than those without risk (22 % vs 4% and 36% vs 13%, respectively). In contrast, the use of aspirin was not significantly different between the groups (27% vs. 19%), suggesting either that these passengers were already on aspirin for another reason or alternatively that passengers with and without risk factors may have considered aspirin relatively harmless and potentially beneficial.
In conclusion, the study shows that preventive measures (medical and non-medical) for air travel-related thrombosis are widely used. A lack of consensus is apparent from the wide variation in thromboprophylaxis use by nationality and professional background.
Prospective studies with anticoagulants, especially in predefined high-risk groups (thrombophilia, obesity, prior thrombosis, or hormonal therapy) are therefore recommended. Guidelines for passengers based on risk assessment approved by expert consensus are necessary. In the meantime, passengers with risk factors should be advised on the potential risk of long-haul flights and available prophylactic measures.
About Chiara Piovella, MD: Dr Piovella completed her medical Internship, Residency, and Fellowship in Internal Medicine at the I.R.C.C.S Policlinico San Matteo in Pavia, Italy. She worked as a fellow in the Thromboembolic Disease Unit of Policlinico San Matteo in Pavia. Her major research effort this past year has been related to heparin-induced thrombocytopenia. Dr. Piovella is currently a Venous Thromboembolism Research Group Fellow.