Assess if a variable confounds a relationship

is_confounder(.tdy_dag, z, x, y, direct = FALSE)

Arguments

.tdy_dag

input graph, an object of class tidy_dagitty or dagitty

z

a character vector, the potential confounder

x, y

a character vector, the variables z may confound.

direct

logical. Only consider direct confounding? Default is FALSE

Value

Logical. Is the variable a confounder?

Examples

dag <- dagify(y ~ z, x ~ z) is_confounder(dag, "z", "x", "y")
#> [1] TRUE
is_confounder(dag, "x", "z", "y")
#> [1] FALSE