derive_var_merged_exist_flag: Merge an Existence Flag

In admiral: ADaM in R Asset Library

Merge an Existence Flag

Description

Adds a flag variable to the input dataset which indicates if there exists at least one observation in another dataset fulfilling a certain condition.

Note: This is a wrapper function for the more generic derive_vars_merged().

Usage

derive_var_merged_exist_flag(
  dataset,
  dataset_add,
  by_vars,
  new_var,
  condition,
  true_value = "Y",
  false_value = NA_character_,
  missing_value = NA_character_,
  filter_add = NULL
)

Arguments

dataset	Input dataset The variables specified by the by_vars argument are expected to be in the dataset.
dataset_add	Additional dataset The variables specified by the by_vars argument are expected.
by_vars	Grouping variables
new_var	New variable The specified variable is added to the input dataset.
condition	Condition The condition is evaluated at the additional dataset (dataset_add). For all by groups where it evaluates as TRUE at least once the new variable is set to the true value (true_value). For all by groups where it evaluates as FALSE or NA for all observations the new variable is set to the false value (false_value). The new variable is set to the missing value (missing_value) for by groups not present in the additional dataset.
true_value	True value
false_value	False value
missing_value	Value used for missing information The new variable is set to the specified value for all by groups without observations in the additional dataset.
filter_add	Filter for additional data Only observations fulfilling the specified condition are taken into account for flagging. If the argument is not specified, all observations are considered.

Details

1. The additional dataset is restricted to the observations matching the filter_add condition.

2. The new variable is added to the input dataset and set to the true value (true_value) if for the by group at least one observation exists in the (restricted) additional dataset where the condition evaluates to TRUE. It is set to the false value (false_value) if for the by group at least one observation exists and for all observations the condition evaluates to FALSE or NA. Otherwise, it is set to the missing value (missing_value).

Value

The output dataset contains all observations and variables of the input dataset and additionally the variable specified for new_var derived from the additional dataset (dataset_add).

See Also

General Derivation Functions for all ADaMs that returns variable appended to dataset: derive_var_extreme_flag(), derive_var_joined_exist_flag(), derive_var_merged_ef_msrc(), derive_var_obs_number(), derive_var_relative_flag(), derive_vars_cat(), derive_vars_computed(), derive_vars_joined(), derive_vars_joined_summary(), derive_vars_merged(), derive_vars_merged_lookup(), derive_vars_merged_summary(), derive_vars_transposed()

Examples

library(dplyr, warn.conflicts = FALSE)

dm <- tribble(
  ~STUDYID,  ~DOMAIN,  ~USUBJID, ~AGE,   ~AGEU,
  "PILOT01",    "DM", "01-1028",   71, "YEARS",
  "PILOT01",    "DM", "04-1127",   84, "YEARS",
  "PILOT01",    "DM", "06-1049",   60, "YEARS"
)

ae <- tribble(
  ~STUDYID,  ~DOMAIN,  ~USUBJID,    ~AETERM,     ~AEREL,
  "PILOT01",    "AE", "01-1028", "ERYTHEMA", "POSSIBLE",
  "PILOT01",    "AE", "01-1028", "PRURITUS", "PROBABLE",
  "PILOT01",    "AE", "06-1049",  "SYNCOPE", "POSSIBLE",
  "PILOT01",    "AE", "06-1049",  "SYNCOPE", "PROBABLE"
)


derive_var_merged_exist_flag(
  dm,
  dataset_add = ae,
  by_vars = exprs(STUDYID, USUBJID),
  new_var = AERELFL,
  condition = AEREL == "PROBABLE"
) %>%
  select(STUDYID, USUBJID, AGE, AGEU, AERELFL)

vs <- tribble(
  ~STUDYID,  ~DOMAIN,  ~USUBJID,      ~VISIT, ~VSTESTCD, ~VSSTRESN, ~VSBLFL,
  "PILOT01",    "VS", "01-1028", "SCREENING",  "HEIGHT",     177.8,      NA,
  "PILOT01",    "VS", "01-1028", "SCREENING",  "WEIGHT",     98.88,      NA,
  "PILOT01",    "VS", "01-1028",  "BASELINE",  "WEIGHT",     99.34,     "Y",
  "PILOT01",    "VS", "01-1028",    "WEEK 4",  "WEIGHT",     98.88,      NA,
  "PILOT01",    "VS", "04-1127", "SCREENING",  "HEIGHT",     165.1,      NA,
  "PILOT01",    "VS", "04-1127", "SCREENING",  "WEIGHT",     42.87,      NA,
  "PILOT01",    "VS", "04-1127",  "BASELINE",  "WEIGHT",     41.05,     "Y",
  "PILOT01",    "VS", "04-1127",    "WEEK 4",  "WEIGHT",     41.73,      NA,
  "PILOT01",    "VS", "06-1049", "SCREENING",  "HEIGHT",    167.64,      NA,
  "PILOT01",    "VS", "06-1049", "SCREENING",  "WEIGHT",     57.61,      NA,
  "PILOT01",    "VS", "06-1049",  "BASELINE",  "WEIGHT",     57.83,     "Y",
  "PILOT01",    "VS", "06-1049",    "WEEK 4",  "WEIGHT",     58.97,      NA
)
derive_var_merged_exist_flag(
  dm,
  dataset_add = vs,
  by_vars = exprs(STUDYID, USUBJID),
  filter_add = VSTESTCD == "WEIGHT" & VSBLFL == "Y",
  new_var = WTBLHIFL,
  condition = VSSTRESN > 90,
  false_value = "N",
  missing_value = "M"
) %>%
  select(STUDYID, USUBJID, AGE, AGEU, WTBLHIFL)

admiral documentation built on May 28, 2026, 9:08 a.m.