Moving from the Single-Mediator to the Multi-mediator Question

Building on Chap.  3 , this chapter addresses the scenario of multiple mediators between exposure and outcome. The primary method introduced is path-specific effect modeling for the case of sequential mediators, detailing the more complex notations, decomposition schemes, identification assumptions, and the natural effect modeling strategies. Additionally, the interventional (in)direct effect modeling for sequential mediators is introduced. An illustrative case is provided.