Air travel and the risk of deep vein thrombosis

Abstract

BACKGROUND: The magnitude of the risk of venous thromboembolism (VTE) following air travel has been difficult to resolve due to a lack of adequate data. We determine the association more precisely by using a large dataset and an improved method of analysis. METHOD: Data on air-travel history for each of 5,196 patients hospitalised for VTE in Western Australia from 1981 to 1999 is analysed using a log-linear regression model for the probability that a flight triggers VTE and for the baseline hazard rate for VTE hospitalisation. RESULTS: The risk of VTE being triggered on the day of an international flight relative to a flight-free day is 29.8 (95% CI 22.4-37.3). Evidence that this relative ri..