Add character method to h_coxreg_inter_effect

NAMESPACE

@@ -9,6 +9,7 @@ S3method(a_summary,factor)
 S3method(a_summary,logical)
 S3method(a_summary,numeric)
 S3method(as.rtable,data.frame)
+S3method(h_coxreg_inter_effect,character)
 S3method(h_coxreg_inter_effect,factor)
 S3method(h_coxreg_inter_effect,numeric)
 S3method(s_compare,character)

NEWS.md

@@ -7,6 +7,7 @@
 * Updated `summarize_coxreg` to print covariates in data rows for univariate Cox regression with no interactions and content rows otherwise.
 * Removed "baseline status" text from `d_count_abnormal_by_baseline` labels.
 * Improved default sizing of annotation tables in `g_km` and added dynamic scaling of the `surv_med` and `coxph` annotation tables, with customization via the `width_annots` argument.
+* Added method for `character` class to `h_coxreg_inter_effect` enabling `character` covariates in `summarize_coxreg`.
 
 ### Bug Fixes
 * Fixed bug in `split_text_grob` preventing titles and footnotes from being properly formatted and printed by `decorate_grob`.

R/cox_regression_inter.R

@@ -154,6 +154,43 @@ h_coxreg_inter_effect.factor <- function(x,
   )
 }
 
+#' @describeIn cox_regression_inter Estimate the interaction with a `character` covariate. This makes an automatic
+#'   conversion to `factor` and then forwards to the method for factors.
+#'
+#' @param verbose (`logical`)\cr Defaults to `FALSE`, which prints out warnings and messages. It is mainly used
+#'   to print out information about factor casting.
+#'
+#' @note
+#' * Automatic conversion of character to factor does not guarantee results can be generated correctly. It is
+#'   therefore better to always pre-process the dataset such that factors are manually created from character
+#'   variables before passing the dataset to [rtables::build_table()].
+#'
+#' @export
+h_coxreg_inter_effect.character <- function(x,
+                                            effect,
+                                            covar,
+                                            mod,
+                                            label,
+                                            control,
+                                            data,
+                                            verbose = FALSE,
+                                            ...) {
+  y <- as_factor_keep_attributes(x, verbose = verbose)
+  data[[effect]] <- as_factor_keep_attributes(data[[effect]], verbose = FALSE)
+  data[[covar]] <- as_factor_keep_attributes(data[[covar]], verbose = FALSE)
+
+  h_coxreg_inter_effect(
+    x = y,
+    effect = effect,
+    covar = covar,
+    mod = mod,
+    label = label,
+    control = control,
+    data = data,
+    ...
+  )
+}
+
 #' @describeIn cox_regression_inter A higher level function to get
 #'   the results of the interaction test and the estimated values.
 #'

tests/testthat/test-coxreg.R

@@ -455,6 +455,34 @@ testthat::test_that("h_coxreg_inter_effect.numerics works with _:_ in effect lev
   testthat::expect_equal(result[, -1], expected[, -1], ignore_attr = TRUE)
 })
 
+testthat::test_that("h_coxreg_inter_effect works with character covariate", {
+  dta_bladder_raw$covar2 <- as.character(dta_bladder_raw$covar2)
+
+  mod1 <- survival::coxph(survival::Surv(time, status) ~ armcd * covar2, data = dta_bladder_raw)
+  testthat::expect_silent(
+    h_coxreg_extract_interaction(
+      effect = "armcd", covar = "covar2", mod = mod1, control = control_coxreg(),
+      at = list(), data = dta_bladder_raw
+    )
+  )
+  testthat::expect_silent(
+    h_coxreg_inter_effect(
+      x = dta_bladder_raw[["covar2"]],
+      effect = "armcd", covar = "covar2", mod = mod1, control = control_coxreg(),
+      at = list(), data = dta_bladder_raw
+    )
+  )
+
+  mod2 <- survival::coxph(survival::Surv(time, status) ~ armcd * covar2 + strata(covar1), data = dta_bladder_raw)
+  testthat::expect_silent(
+    h_coxreg_inter_effect(
+      x = dta_bladder_raw[["covar2"]],
+      effect = "armcd", covar = "covar2", mod = mod2, data = dta_bladder_raw,
+      at = list(), control = control_coxreg()
+    )
+  )
+})
+
 # h_coxreg_inter_estimations ----
 
 testthat::test_that("h_coxreg_inter_estimations' results identical to soon deprecated estimate_coef", {