Pulmonary embolism at autopsy in a normal population: implications for air travel fatalities.
BACKGROUND
Much attention has been focused on the apparent risk to long-haul air travelers of venous thromboembolism [deep vein thrombosis (DVT) and pulmonary embolism (PE)], following a number of well-publicized cases. However, there is little epidemiological data to elucidate the problem. PE tends to be under-diagnosed as a cause of death in the general population. This study sets out to establish the level of risk of fatal PE among long-haul passengers arriving in the UK, on the basis of a reappraisal of the role of PE in mortality in the general population.


METHODS
Autopsies carried out at Gloucester in 1996-2000 were reviewed to determine age-specific mortality rates for PE for West Gloucestershire. These rates were applied to long-haul air travelers arriving in the UK, for whom the number of passenger-years at risk were calculated, to estimate the expected numbers of deaths in this group.


RESULTS
In 3764 autopsies, PE was the primary cause of death in 221 cases (5.9%), while in 304 (8.1%) it was present as an incidental finding. This suggests that PE was involved in approximately 13.9% of deaths, and is more common with age. Passenger years at risk per annum among long-haul passengers arriving in the UK were estimated (mid-range) at 21,830.482; it was anticipated that 6.55 deaths involving PEs, but not related to air travel, could be expected annually in this group.


CONCLUSIONS
It appears that the risks of venous thromboembolism due to air travel are overstated. Some deaths are bound to occur inflight, but there is no evidence to suggest an increase, though clearly there are predisposing risk factors for DVT present on long journeys.
Pheby
D F H
DF
Unit of Applied Epidemiology, University of the West of England, Frenchay Campus, Bristol, England. Derek.Pheby@uwe.ac.uk
Codling
B W
BW
D000293:Adolescent; D000328:Adult; D000337:Aerospace Medicine; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000453:epidemiology* / Q000401:mortality; D012307:Risk Factors; D013923:Thromboembolism / Q000453:epidemiology*; D020246:Venous Thrombosis / Q000453:epidemiology*