Restrict cohort to only the first cohort record per subject

Filter the cohort table keeping only the first cohort record per subject.

Usage

requireIsFirstDrugEntry(
  cohort,
  cohortId = NULL,
  name = omopgenerics::tableName(cohort)
)

Arguments

cohort

A cohort table in a cdm reference.

cohortId

IDs of the cohorts to modify. The default is NULL meaning all cohorts will be used; otherwise, only the specified cohorts will be modified, and the rest will remain unchanged.

name

Name of the table with the filtered cohort records. The default name is the original cohort name, where the original table will be overwritten.

Value

The cohort table having applied the first entry requirement.

Examples

# \donttest{
library(DrugUtilisation)
library(dplyr)

cdm <- mockDrugUtilisation()

cdm$cohort1 <- cdm$cohort1 |>
  requireIsFirstDrugEntry()

attrition(cdm$cohort1) |> glimpse()
#> Rows: 6
#> Columns: 7
#> $ cohort_definition_id <int> 1, 1, 2, 2, 3, 3
#> $ number_records       <int> 3, 3, 2, 2, 5, 5
#> $ number_subjects      <int> 3, 3, 2, 2, 5, 5
#> $ reason_id            <int> 1, 2, 1, 2, 1, 2
#> $ reason               <chr> "Initial qualifying events", "require is the firs…
#> $ excluded_records     <int> 0, 0, 0, 0, 0, 0
#> $ excluded_subjects    <int> 0, 0, 0, 0, 0, 0
# }