The BEST study--a prospective study to compare business class versus economy class air travel as a cause of XXXX .

@entity1 @entity5337 @entity117 @entity49 @entity1150 @entity358 @entity715 @entity5582
BACKGROUND: As many as 10% of airline passengers travelling without prophylaxis for long distances may develop a @entity49 . There is, however, no evidence that economy class travellers are at increased risk of @entity715 . OBJECTIVES: A suitably powered prospective study, based on the incidence of @entity1150 ( @entity1150 ) reported in previous studies on long-haul flights, was designed to determine the incidence of positive venous duplex scans and D-dimer elevations in low and intermediate-risk passengers, comparing passengers travelling in business and economy class. @entity1 /METHODS: Eight hundred and ninety-nine passengers were recruited (180 travelling business class and 719 travelling economy). D-dimers were measured before and after the flight. A value greater than 500 ng/ml was accepted as abnormal. A @entity49 screen was conducted which included the @entity5337 mutation, the prothombin 20210A mutation, protein C and S levels, @entity5582 levels, and anticardiolipin antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM). On arrival, lower limb compression ultrasonography of the deep veins was performed. Logistical regression analysis was used to determine the risk factors related to abnormally high D-dimer levels. RESULTS: Only 434 subjects had a full venous duplex scan performed. None had ultrasonic evidence of @entity49 . Nine passengers tested at departure had elevated D-dimer levels and these volunteers were excluded from further study. Seventy-four of the 899 passengers had raised D-dimers on arrival. Twenty-two of 180 business class passengers (12%) developed elevated D-dimers compared with 52 of 719 economy class passengers (7%). There was no significant association between elevation of D-dimers and the class flown (odds ratio (OR) 0.61, p = 0.109). The @entity5337 mutation, factor VIII levels and the use of @entity117 were, however, associated with raised D-dimers (OR 3.36, p = 0.024; OR 1.01, p = 0.014; and OR 2.04, p = 0.038, respectively). Five hundred and five passengers were contacted within 6 months and none reported any symptoms of a clinical @entity715 or @entity358 . CONCLUSION: The incidence of ultrasonically proven @entity1150 is much lower than previously reported. However, more than 10% of all passengers developed raised D-dimers, which were unrelated to the class flown. A rise in D-dimers is associated with an inherent risk of @entity715 and/or @entity49 , demonstrates activation of both the coagulation and fibrinolytic systems during long-haul flights, and may indicate the development of small thrombi.
