Adds an indirect effect index to a fitted mediation model

add_index is a generic function that adds a (moderated) indirect effect index to an object created with an mdt_* family function. This index is computed using Monte Carlo methods. This function invokes particular methods depending of the class of the mediation model. For example, with a model fitted with mdt_simple, add_index will invoke add_index.simple_mediation.

add_index(mediation_model, times = 5000, level = 0.05, ...)

Arguments

mediation_model: A mediation model fitted with an mdt_* family function.
times: Number of simulations to use to compute the Monte Carlo index's confidence interval.
level: Alpha threshold to use for the confidence interval.
...: Further arguments to be passed to specific methods.

Value

An object of the same class as mediation_model, but with index added for later use.