Confounding can be Confounding - Several Risk Factors

Abstract

This chapter considers how the assessment of confounding gets somewhat more complicated when controlling for more than one risk factor. In particular, when several risk factors are being controlled, we may find that considering all risk factors simultaneously may not lead to the same conclusion as when considering risk factors separately. We have previously (Chapter 10) argued that the assessment of confounding is not appropriate for variables that are effect modifiers of the exposure-disease relationship under study. Consequently, throughout this chapter, our discussion of confounding will assume that none of the variables being considered for control are effect modifiers (i.e., there is no interaction between exposure and any variable being controlled).