Is there a way to specify statistics format by column in gtsummary::tbl_summary?

Question

I have multiple columns created from the "by" variable that I want mean() and sd(), but in one column (the last) I just want the mean(). Is there a way to format statistics by column as opposed to row with tbl_summary()?

df <- data.frame(
     group = rep(c("A", "B", "C"), each = 10),
     var1 = rnorm(30, mean = 5, sd = 2),
     var2 = rnorm(30, mean = 7, sd = 1),
     var3 = rnorm(30, mean = 9, sd = 3)) 

df |>
  tbl_summary(
    by = group,
    statistic = all_continuous() ~ "{mean} ({sd})"
  )

So with the above is there a way to display just {mean} for Group == "C" while keeping {mean} ({sd}) statistics for Group = c("A", "B")?

Answer 1

You could create separate tables and then merge them:

library(gtsummary)

df |>
  subset(group != "C") |>
  tbl_summary(
    by = group,
    statistic = all_continuous() ~ "{mean} ({sd})"
  ) -> gts1

df |>
  subset(group == "C") |>
  tbl_summary(
    by = group,
    statistic = all_continuous() ~ "{mean}"
  ) -> gts2


tbl_merge(list(gts1, gts2)) |> 
  modify_spanning_header(everything() ~ NA_character_)

^{Created on 2024-09-24 with reprex v2.0.2}