dag {
bb="-3,-0.5,2,1.2"
D [outcome,pos="1.000,1.000"]
E [exposure,pos="-2.000,1.000"]
Z [pos="-0.500,0.500"]
D <-> Z [pos="1.000,-1.000"]
E -> D
E <-> Z [pos="-2.000,-1.000"]
}
