Figure 1.
DAGs illustrating relationship between covariates and outcomes. Upper panel: Our proposed data generation mechanism in which y(0) influences z beyond the error correlation. Lower panel: A depiction of how the CSEM can be fitted to allow for the possibility of the influence of y(0) on z as per the upper panel, but without the feedback loop (all covariates of x and w are placed in the medication use model). Solid black circles indicate observed variables; dashed black circles indicate partially observed variables. The double arrow denotes correlation in the error terms. Note that the covariates of x, w, and v need not be unique, The upper-left arrow between x and y(0) in each DAG corresponds to the association of interest.
