Factors that explain the power line configuration wiring code-childhood leukemia association: what would they look...

We explore the question of how to characterize a factor that would explain the patterns of wire code-childhood leukemia association observed in three major United States case-control studies. In positive studies, such a factor needs to be more prevalent in "high" wire codes than "low" whereas in negative studies, the factor should not be correlated to wire code. These concepts are quantified and we use these results to characterize potential factors that might explain the wire code-childhood leukemia association. We then re-evaluate findings from a survey of correlates of wire code in Connecticut with respect to potential for explaining the wire code-leukemia association. Under the presumption that the Connecticut correlations apply to the populations in which a wire code-leukemia association has been observed, only age and type of home are correlated enough to be potential explanatory factors. In particular, it appears very unlikely that traffic density can explain a significant portion of the wire code association. We suggest that correlation studies can be useful for identifying potential explanatory factors, but they must be done in regions where a wire code-childhood leukemia association has been observed.