On the other hand, the use of individual data on famine exposure rather than grouping populations according to place of residence or time is a strength of our study since we used a more precise exposure measurement.
With the technological advancement of real-time vector signal analyzers, a more precise exposure evaluation has become achievable.
By collecting more detailed information on location, number and types of premises that were affected by changes in closing hours, we have probably obtained a more precise exposure measure and relevant control measure than is often the case in such studies.
The road distance buffers tested here and used in comparable studies (Finkelstein et al. 2004) did produce elevated risks, but with less certainty than with the predicted NO2 concentrations, as would be expected from a less precise exposure estimator (Molitor et al. 2007).
However, other recent studies have suggested that considering a more precise exposure model focused on the home address might not improve health effects estimates in terms of bias and variance (Kim et al. 2009; Lepeule et al. 2010; Szpiro et al. 2011).
In these types of studies, there is a need for more precise exposure assessment.
Compared with prior studies, we were able to isolate the effects of a relatively homogeneous endocrine disruptor for which the precise exposure is known.
One obvious approach to the problem is to obtain more precise exposure estimates instead of correcting for a known or suspected extent of exposure miss-measurement.
This could be due to more precise exposure estimation, or it could reflect a cumulative effect of PMTRA on subclinical inflammation.
The FOEN is currently refining its models, and more precise exposure data will be available for a validation of the results from the next SAPALDIA follow-up assessment currently being conducted (SAPALDIA 3, 2010 2011).
