clukyanenko.R

library(gtsummary)
library(tidyverse)

trial %>%
  tbl_strata(
    strata = trt,
    ~ .x %>%
      nest(data = -grade) %>%
      arrange(grade) %>%
      rowwise() %>%
      mutate(
        # within Grade, summarize tumor response
        tbl = 
          tbl_summary(data, 
                      include = response, 
                      missing = "no",
                      statistic = response ~ "{p}% ({n}/{N})",
                      label = list("response" = paste("Grade", as.character(grade)))) %>%
          list()
      ) %>%
      # stack the tbls within each grade into a single tbl
      pull(tbl) %>%
      tbl_stack()
  ) %>%
  # remove default spanning header and footnote
  modify_spanning_header(everything() ~ NA) %>%
  modify_footnote(everything() ~ NA) %>%
  # update the column headers and add a table title
  modify_header(stat_0_1 = "Drug A", stat_0_2 = "Drug B", label = "") %>%
  modify_caption("Tumor Response Rate by Treatment and Grade")