derrick

derrick is a focused export layer for clinical tables. Build an analysis table with gtsummary or a plain data frame, then use gtsummary_reporter() to write consistent reporter RTF, TXT, DOCX, PDF, and HTML outputs.

The package is designed for the output details that usually slow down clinical reporting work:

• one table specification can produce RTF, TXT, DOCX, PDF, and HTML files;
• gtsummary labels, p-values, indentation, and spanning headers are carried into the report output;
• page geometry, margins, manual column widths, and TXT character budgets can be controlled explicitly;
• titles, footnotes, program names, timestamps, and optional RDS exports are handled in one call.

Installation

install.packages("remotes")
remotes::install_github("openpharma/derrick")

library(derrick)

Quick Start

The main workflow is:

1. create or receive a gtsummary table;
2. set optional report metadata in the caller environment;
3. call gtsummary_reporter() with the required output formats.

library(dplyr)
library(gtsummary)
library(derrick)

dir.create("outputs", showWarnings = FALSE)

title1 <- "Table 14.1 Summary of Demographics"
footnote1 <- "Percentages are based on the number of subjects in each treatment group."
progname <- "programs/t-demog.R"

tbl <- gtsummary::trial |>
  dplyr::select(trt, age, grade) |>
  gtsummary::tbl_summary(by = trt) |>
  gtsummary::add_p() |>
  gtsummary::modify_spanning_header(
    gtsummary::all_stat_cols() ~ "**Treatment Group**"
  )

paths <- gtsummary_reporter(
  gts_obj = tbl,
  file_path = "outputs/t-demog.rtf",
  output_types = c("RTF", "TXT", "DOCX", "PDF", "HTML"),
  save_rds = TRUE
)

paths

This writes outputs/t-demog.rtf, outputs/t-demog.txt, outputs/t-demog.docx, outputs/t-demog.pdf, and outputs/t-demog.html. With save_rds = TRUE, the processed output data is also saved beside the report, and ARD data is saved when it can be extracted from the input table.

What derrick Preserves

For gtsummary inputs, derrick reads both table_body and table_styling. That means the exported report can use the visible column order, display labels, row indentation rules, p-value columns, and spanning header metadata already defined by the analysis table.

Plain data frames are also supported when the table has already been assembled:

tbl_df <- data.frame(
  label = c("Age", "  Mean (SD)", "Sex", "  Female"),
  stat_1 = c("", "42.1 (12.3)", "", "10 (50.0%)"),
  stat_2 = c("", "43.8 (11.9)", "", "12 (60.0%)"),
  stringsAsFactors = FALSE
)

gtsummary_reporter(
  gts_obj = tbl_df,
  file_path = "outputs/simple-table.rtf",
  output_types = c("RTF", "TXT", "HTML"),
  column_labels = c(label = "Characteristic", stat_1 = "Placebo", stat_2 = "Active"),
  spanning_headers = data.frame(
    from = "stat_1",
    to = "stat_2",
    label = "Treatment Group"
  )
)

Layout Controls

Use defaults first. By default, derrick lets reporter calculate table and column widths for the requested output format. Supply width arguments only when the report shell requires a specific layout.

Argument	Use when
output_types	You need one or more of "RTF", "TXT", "DOCX", "PDF", or "HTML".
max_table_width	You need a table narrower than the printable page.
column_widths	You need exact column allocation, e.g. `"3
max_chars_per_line	TXT output must fit a fixed character budget, such as 132 columns.
report_orientation, report_paper_size, report_margins	The table must match a specific page setup.
rows_per_page	You need manual row chunks before reporter writes the final files.

Reporter-managed widths, wrapping, and pagination are used by default. max_chars_per_line only constrains TXT output. Leave rows_per_page = NULL unless a table needs fixed row chunks for a specific deliverable.

Metadata and Diagnostics

gtsummary_reporter() automatically looks for title1 through title9, footnote1 through footnote9, and progname in the caller environment. Title and footnote wrapping is handled by reporter when the report is written.

For layout validation, use:

gtsummary_reporter(tbl, "outputs/check.rtf", debug_indent = TRUE)
gtsummary_reporter(tbl, "outputs/check.rtf", debug_spanning = TRUE)

Learn More

See vignettes/clinical-table-workflow.Rmd for the draft end-to-end workflow, including column width strategy, plain data frame inputs, pagination choices, and troubleshooting notes.