Nonetheless, the literature is inconsistent on all of these associations. Among possible reasons both the lack of formal
theoretical hypotheses and, somewhat in contrast, an incomplete set of risk factors are suggested (possibly stemming
from excessive reliance on a priori models in this relatively early stage of accruing evidence) [9, 16]. Many of these studies have analyzed data from the general population, where the separate contributions of working conditions and
socioeconomic status (SES) may be difficult to disentangle, even with multivariable statistical methods. Further, potential
effect modification within these associations has been largely ignored, with the exception of comparing risks between men
and women.