Create a parameter object for the function matchOnPs()

Create a parameter object for the function matchOnPs()

Usage

createMatchOnPsArgs(
  caliper = 0.2,
  caliperScale = "standardized logit",
  maxRatio = 1,
  allowReverseMatch = FALSE,
  matchColumns = c(),
  matchCovariateIds = c()
)

Arguments

caliper

The caliper for matching. A caliper is the distance which is acceptable for any match. Observations which are outside of the caliper are dropped. A caliper of 0 means no caliper is used.

caliperScale

The scale on which the caliper is defined. Three scales are supported: caliperScale = 'propensity score', caliperScale = 'standardized', or caliperScale = 'standardized logit'. On the standardized scale, the caliper is interpreted in standard deviations of the propensity score distribution. 'standardized logit' is similar, except that the propensity score is transformed to the logit scale because the PS is more likely to be normally distributed on that scale (Austin, 2011).

maxRatio

The maximum number of persons in the comparator arm to be matched to each person in the treatment arm. A maxRatio of 0 means no maximum: all comparators will be assigned to a target person.

allowReverseMatch

Allows n-to-1 matching if target arm is larger

matchColumns

Names or numbers of one or more columns in the data data.frame on which subjects should be stratified prior to matching. No persons will be matched with persons outside of the strata identified by the values in these columns.

matchCovariateIds

One or more covariate IDs in the cohortMethodData object on which subjects should be also matched.

Value

An object of type MatchOnPsArgs.

Details

Create an object defining the parameter values.

References

Austin, PC. (2011) Optimal caliper widths for propensity-score matching when estimating differences in means and differences in proportions in observational studies, Pharmaceutical statistics, March, 10(2):150-161.