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Create an Existence Flag

Source: R/get_flagged_records.R
get_flagged_records.Rd

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

Note: This is a helper function for derive_vars_merged_exist_flag() which inputs this result into derive_vars_merged().

Usage 

get_flagged_records(dataset, new_var, condition, filter = NULL)

Arguments

dataset

Input dataset

Default value

none

new_var

New variable

The specified variable is added to the input dataset.

Default value

none

condition

Condition

The condition is evaluated at the dataset (dataset). For all rows where it evaluates as TRUE the new variable is set to 1 in the new column. Otherwise, it is set to 0.

Comparing derived numeric variables to fixed values, e.g., PCHG <= -90, may give unexpected results due to floating point representation. For details and solutions see the "Floating Point Comparisons" section in vignette("concepts_conventions").

Default value

none

filter

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.

Comparing derived numeric variables to fixed values, e.g., PCHG <= -90, may give unexpected results due to floating point representation. For details and solutions see the "Floating Point Comparisons" section in vignette("concepts_conventions").

Permitted values

a condition

Default value

NULL

Value

The output dataset is the input dataset filtered by the filter condition and with the variable specified for new_var representing a flag for the condition.

See also

Utilities used within Derivation functions: as_admiral_df(), extract_unit(), get_not_mapped(), get_vars_query()

Examples 


library(dplyr, warn.conflicts = FALSE)


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"
)


get_flagged_records(
  dataset = ae,
  new_var = AERELFL,
  condition = AEREL == "PROBABLE"
) %>%
  select(STUDYID, USUBJID, AERELFL)
#> # A tibble: 4 × 3
#>   STUDYID USUBJID AERELFL
#>   <chr>   <chr>     <dbl>
#> 1 PILOT01 01-1028       0
#> 2 PILOT01 01-1028       1
#> 3 PILOT01 06-1049       0
#> 4 PILOT01 06-1049       1

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
)
get_flagged_records(
  dataset = vs,
  new_var = WTBLHIFL,
  condition = VSSTRESN > 90,
  filter = VSTESTCD == "WEIGHT" & VSBLFL == "Y"
) %>%
  select(STUDYID, USUBJID, WTBLHIFL)
#> # A tibble: 3 × 3
#>   STUDYID USUBJID WTBLHIFL
#>   <chr>   <chr>      <dbl>
#> 1 PILOT01 01-1028        1
#> 2 PILOT01 04-1127        0
#> 3 PILOT01 06-1049        0