These studies varied with respect to exposure, effect measures, time delayed between exposure and study and in study design.
Once an asthmagen is recognized, issues with respect to exposure, dose response, and route of exposure need to be resolved in order to implement appropriate controls.
This type of misclassification is likely to be random with respect to exposure and would make the effect of exposure harder to detect.
This group is highly heterogeneous with respect to exposure due to their varying opportunity for direct exposure to 2,4-D.
Conversely, our "experienced" and "inexperienced" males differed with respect to exposure to females, but also differed with respect to exposure to any other adult flies, so a response to experience in our experiment need not have been due to response to an appropriate mating partner.
Any misclassification of pregnancy complications is unlikely to be differential with respect to exposure status, as participants were generally unaware of their exposure to PCE-contaminated drinking water [ 15].
Even in the absence of reverse causation, the increasing interval between the relevant and measured exposures is a form of measurement error nondifferential with respect to exposure or disease status that could attenuate the observed associations.
The second class of methods includes profile regression, which partitions observations into clusters that are relatively coherent with respect to exposure among observations within clusters and dissimilar with respect to exposure between clusters (Molitor et al. 2010).
This misclassification is, in expectation, non-differential with respect to exposure because we blinded the reviewed medical records with respect to exposure status.
With respect to exposure assessment, we were able to collect individual data on occupational exposure to the air disaster.
