Stratify persons by propensity score and other covariates

Use the provided propensity scores and covariates to stratify persons.

stratifyByPsAndCovariates(
  population,
  numberOfStrata = 5,
  baseSelection = "all",
  cohortMethodData,
  covariateIds
)

Arguments

population

A data frame with the three columns described below

numberOfStrata

Into how many strata should the propensity score be divided? The boundaries of the strata are automatically defined to contain equal numbers of target persons.

baseSelection

What is the base selection of subjects where the strata bounds are to be determined? Strata are defined as equally-sized strata inside this selection. Possible values are "all", "target", and "comparator".

cohortMethodData

An object of type CohortMethodData as generated using getDbCohortMethodData().

covariateIds

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

Value

Returns a date frame with the same columns as the input population plus one extra column: stratumId.

Details

The data frame should have the following three columns:

• rowId (numeric): A unique identifier for each row (e.g. the person ID).

• treatment (integer): Column indicating whether the person is in the target (1) or comparator (0) group.

• propensityScore (numeric): Propensity score.