WHO Research into global hazards of travel (WRIGHT) project
Final report of Phase I The objectives of the WRIGHT (WHO
Research Into Global Hazards of Travel) project were to confirm
that the risk of venous thromboembolism (VTE) is increased by
air travel and to determine the magnitude of risk, the effect of
other factors on the risk and to study the effect of preventive
measures on risk. To address these objectives, several studies
were performed during Phase I of the WRIGHT project. Additional
proposed studies related to the effect of preventive
interventions were deferred to Phase II. The findings of the
epidemiological studies indicate that the risk of VTE
approximately doubles after a long-haul flight (>4 hours) and
also with other forms of travel where travellers are exposed to
prolonged seated immobility. The risk increases with the
duration of the travel and with multiple flights within a short
period. The risk also increases significantly in the presence of
other known risk factors of VTE. The risk fa