Health-Exposure Modelling and the Ecological Fallacy

Publication Year:
2005
Usage 691
Abstract Views 619
Downloads 72
Repository URL:
http://biostats.bepress.com/uwbiostat/paper272
Author(s):
Wakefield, Jon; Shaddick, Gavin
Publisher(s):
bepress
Tags:
Ecological fallacy; Environmental epidemiology; Exposure modelling; Quasi-likelihood; Spatial Epidemiology; Disease Modeling; Epidemiology
article description
Recently there has been increased interest in modelling the association between aggregate disease counts and environmental exposures measured, for example via air pollution monitors, at point locations. This paper has two aims: first we develop a model for such data in order to avoid ecological bias; second we illustrate that modelling the exposure surface and estimating exposures may lead to bias in estimation of health effects. Design issues are also briefly considered, in particular the loss of information in moving from individual to ecological data, and the at-risk populations to consider in relation to the pollution monitor locations. The approach is investigated initially through simulations, and is then applied to a study of the association between mortality in the over 65’s in the year 2000, and the previous year’s SO2, in London. We conclude that the use of the proposed model can provide valid inference, but the use of estimated exposures should be carried out with great caution.