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Derive Change from Baseline

Source: R/derive_var_chg.R
derive_var_chg.Rd

Derive change from baseline (CHG) in a BDS dataset

Usage

derive_var_chg(dataset)

Arguments

dataset

The input dataset. Required variables are AVAL and BASE.

Value

The input dataset with an additional column named CHG

Details

Change from baseline is calculated by subtracting the baseline value from the analysis value.

See also

BDS-Findings Functions that returns variable appended to dataset: derive_var_analysis_ratio(), derive_var_anrind(), derive_var_atoxgr_dir(), derive_var_atoxgr(), derive_var_basetype(), derive_var_base(), derive_var_ontrtfl(), derive_var_pchg(), derive_var_shift()

Examples

library(tibble)

advs <- tribble(
  ~USUBJID, ~PARAMCD, ~AVAL, ~ABLFL, ~BASE,
  "P01",    "WEIGHT", 80,    "Y",    80,
  "P01",    "WEIGHT", 80.8,  "",     80,
  "P01",    "WEIGHT", 81.4,  "",     80,
  "P02",    "WEIGHT", 75.3,  "Y",    75.3,
  "P02",    "WEIGHT", 76,    "",     75.3
)
derive_var_chg(advs)
#> # A tibble: 5 x 6
#>   USUBJID PARAMCD  AVAL ABLFL  BASE   CHG
#>   <chr>   <chr>   <dbl> <chr> <dbl> <dbl>
#> 1 P01     WEIGHT   80   "Y"    80   0    
#> 2 P01     WEIGHT   80.8 ""     80   0.800
#> 3 P01     WEIGHT   81.4 ""     80   1.4  
#> 4 P02     WEIGHT   75.3 "Y"    75.3 0    
#> 5 P02     WEIGHT   76   ""     75.3 0.7