add statistical results in the grand summary row

[robpetrosino]

I need to run a simple paired t-test on two columns of my table (see fig below), and I want it to be in the grand summary row (below the correlation).

Here's a minimal working example for you to play with:

library(tidyverse)
library(gt)
library(rstatix)

df <- structure(list(study = c("caius", "titium", "sempronius", "cicero", 
"titus"), control = c(452, 603, 243, 552, 173), treatment = c(482, 
383, 579, 360, 227), difference = c(30, -220, 336, -192, 54)), class = "data.frame", row.names = c(NA, 
-5L))

df %>% gt() %>%
  grand_summary_rows(
    columns = c(control, treatment, difference),
    fns = list(Mean ~ round(mean(.)),
               SD ~ round(sd(.))), 
    missing_text = " " 
  ) %>%
  grand_summary_rows(
    columns = c(difference),
    fns = list(Correlation ~ round(cor(control, treatment), 2)), 
    missing_text = " " 
  )
  

I guess that running the test within gt might be complicated, so I wanted to add the results as a string in the grand summary row, is there any way I could hard code that?

Thanks!