make_match_distances function

Make match distances within strata

Makes the match distance with strata specifications for strata_match. This function is largely unecessary to call outside of stratamatch, but it is exported for the benefit of the user to aid in debugging. Note that this function requires that the R package optmatch is installed.

make_match_distances(object, model, method)

Arguments

• object: a strata object

• model: (optional) formula for matching. If left blank, all

  columns of the analysis set in object will be used as covariates in the propensity model or mahalanobis match (except outcome, treatment and stratum)

• method: either "prop" for propensity score matching based on a glm fit with model model, or "mahal" for mahalanobis distance matching by the covariates in model.

Returns

a match distance matrix for optmatch

Examples

dat <- make_sample_data(n = 75)

# stratify with auto_stratify
a.strat <- auto_stratify(dat, "treat", outcome ~ X2, size = 25)

# make match distances.  Requires optmatch package to be installed.

md <- make_match_distances(a.strat, treat ~ X1 + X2, method = "mahal")

See Also

https://cran.r-project.org/package=optmatch