Helper for Finding AVISIT after which CHG are all Missing

Helper for Finding AVISIT after which CHG are all Missing

Usage

find_missing_chg_after_avisit(df)

Arguments

df

(`data.frame`)
with `CHG` and `AVISIT` variables.

Value

A string with either the factor level after which `AVISIT` is all missing, or `NA`.

Examples

df <- data.frame(
  AVISIT = factor(c(1, 2, 3, 4, 5)),
  CHG = c(5, NA, NA, NA, 3)
)
find_missing_chg_after_avisit(df)
#> [1] NA

df2 <- data.frame(
  AVISIT = factor(c(1, 2, 3, 4, 5)),
  CHG = c(5, NA, 3, NA, NA)
)
find_missing_chg_after_avisit(df2)
#> [1] "4"

df3 <- data.frame(
  AVISIT = factor(c(1, 2, 3, 4, 5)),
  CHG = c(NA, NA, NA, NA, NA)
)
find_missing_chg_after_avisit(df3)
#> [1] "1"