Assign object name to different tbl_summary tables from lapply function

Question

I would want to generate different tbl_summary tables from a loop(lapply function) over similar categorical variables (var1, var2, var3) applied to "by= " and assign each of them an object name e.g "tbl_var1", "tbl_var2" and "tbl_var3"

dflist <- c("var1", 
        "var2", 
        "var3")

vartbls = lapply(dflist, function(df) {
    tbl_summary_ex2 <-
    trial %>%
        select(age, grade, response, trt) %>%
        tbl_summary(
            by = df,
            label = list(age ~ "Patient Age"),
            statistic = list(all_continuous() ~ "{mean} ({sd})"),
            digits = list(age ~ c(0, 1))
            )
    }
)

Answer 1

Here is a reprex with a working version of your function with code to set the names:

library(gtsummary)
dflist <- c("age", "grade")

vartbls <-  lapply(dflist, function(x) {
  tbl_summary_ex2 <-
    trial %>%
    select(age, grade, response, trt) %>%
    tbl_summary(
      by = x,
      label = list(age ~ "Patient Age"),
      statistic = list(all_continuous() ~ "{mean} ({sd})"),
      digits = list(age ~ c(0, 1))
    )
}
)
names(vartbls) <- paste0("tbl_", dflist)

Here is a version using {purrr} and setting names before iterating:

library(gtsummary)
library(purrr)
result <- c("trt", "grade") %>%
  purrr::set_names(paste0("tbl_", .)) %>%
  purrr::map(., ~ trial %>%
    select(age, grade, response, trt) %>%
    tbl_summary(
      by = .x,
      label = list(age ~ "Patient Age"),
      statistic = list(all_continuous() ~ "{mean} ({sd})"),
      digits = list(age ~ c(0, 1))
    ))