Synovate Healthcare study: Introductory Note
Synovate Healthcare study: The Extent of Aspirin Use for the Prophylaxis of DVT on Long Haul Flights.
The WRIGHT study (World Health Organisation Research Into Global Hazards of Travel) is a multicentred multistudy project investigating the association between travel and venous thromboembolism (VTE)). The project was designed as a series of inter-related studies with the following aims:
- To determine if the risk of venous thrombosis is increased by travel.
- To determine the magnitude of this risk.
- To determine the effect of other factors on the association.
- To clarify the causal mechanisms.
The combined results from this group of recently completed studies is now providing a consistent picture, in line with previous medical literature on traveller's thrombosis, that seated immobility is a risk factor for VTE. When considering the whole population there appears to be an approximately three-fold increase in risk, whatever the form of travel, but this relative risk increases sharply if other risks for VTE are also present. These studies also confirm that the longer the period of travel, the greater the risk.
For air travel, public concern has been raised due to media attention over the past few years. A number of possible interventions have been suggested to reduce the risk but the evidence base for the effectiveness of these interventions is generally weak. This is currently being considered by the Scientific Executive Committee for the WRIGHT programme, as they develop proposals for research aimed at investigating further some of the most promising interventions.
One such intervention is the use of aspirin. Previous studies commissioned by the Aviation Health Working Group (AHWG) have indicated that a proportion of the UK population flying long-haul may already be using aspirin for the prophylaxis of Deep Vein Thrombosis. These studies have also pointed out that its use may be more harmful than beneficial.
Synovate Healthcare were commissioned by the AHWG to carry out a study aimed at quantifying the extent of aspirin usage amongst UK long-haul aircraft passengers, in order to assist the discussions in the AHWG and to assist in the development of public health policy regarding DVT. A total of 1672 face-to-face interviews were conducted between 8th September and 29th November 2004. The study was designed to generate robust estimates of the percentage of travellers within each of four different risk groups who are taking aspirin when they fly long haul.
This report provides for the first time a detailed analysis of the aspirin taking behaviour of UK residents flying long haul out of the UK. Of the total sample analysed, 20% had taken or planned to take aspirin before, during or after their long haul flight. These numbers need to be considered in the context of the evidence for the likely benefit of taking aspirin in this way, weighed against the potential harm. These numbers represent a sufficiently large usage to give cause for concern, and the need for further consideration by the AHWG as part of its future work programme.
