Compute standardized mean differences (SMDs) between the treated and control subjects. Computed as \((\mu_t - \mu_c)/\sigma\) where \(\mu_t\) is the weighted mean among the treated subjects, \(\mu_c\) is the weighted mean among the control subjects, and \(\sigma\) is the standard deviation in the unweighted sample (among the treated subjects only since we are interested in the average treatment effect for the treated).

smd(object, ...)

# S3 method for grouped_psweight_mi
smd(object, x_vars = NULL)

Arguments

object

An object of the appropriate class.

x_vars

A character vector containing the covariates used to check for balance. These must be columns in object. If NULL, then variables that were used to fit the propensity score model(s) are used.

Value

A smd object that inherits from dplyr::tibble. The following columns are always returned:

var

A variable - either a covariate or the propensity score.

method

The propensity score method.

mean_control

The (weighted) mean among the controls.

mean_treat

The (weighted) mean among the treated.

sd_treat

The standard deviation among the treated.

smd

The standardized mean difference.

In addition, a column for the group included if object is grouped and the column imp is included if object was instantiated from a propensity score fit using multiply imputed datasets.