add_split_table: Add split tables around a forest plot

In ggforestplotR: Publication-Ready Forest Plots with 'ggplot2'

Add split tables around a forest plot

Description

Compose split table blocks around a forest plot so that summary data appear on both sides of the plotting panel.

Usage

add_split_table(
  plot = NULL,
  show_terms = TRUE,
  show_n = NULL,
  show_events = NULL,
  show_estimate = TRUE,
  show_p = FALSE,
  left_columns = NULL,
  right_columns = NULL,
  term_header = "Term",
  n_header = "N",
  events_header = "Events",
  estimate_label = NULL,
  p_header = "P-value",
  column_labels = NULL,
  digits = NULL,
  estimate_digits = NULL,
  interval_digits = NULL,
  p_digits = NULL,
  estimate_fmt = NULL,
  ci_fmt = NULL,
  text_size = NULL,
  header_text_size = NULL,
  header_fontface = "bold",
  header_family = NULL,
  striped_rows = NULL,
  stripe_fill = NULL,
  stripe_colour = NULL,
  stripe_alpha = NULL,
  left_width = NULL,
  plot_width = NULL,
  right_width = NULL
)

Arguments

plot	A plot created by ggforestplot(). Leave as NULL to use + add_split_table(...) syntax.
show_terms	Whether to include the term column in the default left-side selection when left_columns is not supplied.
show_n	Whether to include the N column in the default left-side selection when left_columns is not supplied. Defaults to TRUE when the underlying plot data include an n column.
show_events	Whether to include the Events column in the default left-side selection when left_columns is not supplied. Defaults to TRUE when the underlying plot data include an events column.
show_estimate	Whether to include the formatted estimate and confidence interval column in the default right-side selection when right_columns is not supplied.
show_p	Whether to include the p-value column in the default right-side selection when right_columns is not supplied.
left_columns	Optional explicit columns to place on the left side of the forest plot. Accepts built-in names such as "term", "n", "events", "estimate", "ci", and "p", arbitrary original dataframe columns, or positions corresponding to the built-in columns. "conf.low" and "conf.high" are accepted as aliases for "ci".
right_columns	Optional explicit columns to place on the right side of the forest plot. Accepts built-in names such as "estimate", "ci", and "p", arbitrary original dataframe columns, or positions corresponding to the built-in columns. "conf.low" and "conf.high" are accepted as aliases for "ci".
term_header	Header text for the term column.
n_header	Header text for the N column.
events_header	Header text for the Events column.
estimate_label	Header label for the estimate column. Defaults to the model-derived label when available.
p_header	Header text for the p-value column.
column_labels	Optional named vector used to relabel table column headers. Names should match values supplied to left_columns or right_columns after column resolution, such as "term", "estimate", "ci", "p", or an arbitrary original dataframe column.
digits	Deprecated. Number of digits used when formatting estimates and p-values. Defaults to 2. Use estimate_digits, interval_digits, and p_digits for separate control.
estimate_digits	Number of digits used for point estimates.
interval_digits	Number of digits used for confidence interval bounds.
p_digits	Number of digits used for p-values.
estimate_fmt	Format string for the estimate column. Use {estimate}, {conf.low}, and {conf.high} as placeholders. The shorthand ⁠{conf.low, conf.high}⁠ is also supported. Defaults to "{estimate} ({conf.low}, {conf.high})", or "{estimate}" when table columns include "ci".
ci_fmt	Format string for the confidence interval column when table columns include "ci". Use {conf.low} and {conf.high} as placeholders. The shorthand ⁠{conf.low, conf.high}⁠ is also supported. Defaults to "({conf.low}, {conf.high})".
text_size	Text size for table contents. Defaults to 3.2.
header_text_size	Header text size for table column labels. Defaults to 11.
header_fontface	Font face used for table column labels. Defaults to "bold".
header_family	Optional font family used for table column labels.
striped_rows	Whether to draw alternating row stripes behind the split table layout. Defaults to the stripe setting used in ggforestplot().
stripe_fill	Fill colour used for striped rows. Defaults to the stripe fill used in ggforestplot().
stripe_colour	Outline colour for striped rows. Defaults to the stripe outline used in ggforestplot().
stripe_alpha	Transparency for striped rows. Defaults to the stripe alpha used in ggforestplot().
left_width	Optional width allocated to the left table block. By default this is derived from the number of displayed left-side columns relative to plot_width.
plot_width	Optional width allocated to the forest plot panel. Defaults to 2.5.
right_width	Optional width allocated to the right table block. By default this is derived from the number of displayed right-side columns relative to plot_width.

Value

A patchwork-composed plot containing a left table, the forest plot, and a right table, or a ggplot add-on object when plot = NULL.

Examples

coefs <- data.frame(
  term = c("Age", "BMI", "Treatment"),
  estimate = c(0.3, -0.2, 0.4),
  conf.low = c(0.1, -0.4, 0.2),
  conf.high = c(0.5, 0.0, 0.6),
  sample_size = c(120, 115, 98),
  p_value = c(0.012, 0.031, 0.004)
)

p <- ggforestplot(coefs, n = "sample_size", p.value = "p_value")
add_split_table(
  p,
  left_columns = c("term", "n"),
  right_columns = c("estimate", "p"),
  estimate_label = "HR"
)

ggforestplot(coefs, n = "sample_size", p.value = "p_value") +
  add_split_table(
    left_columns = c(1, 2),
    right_columns = c(4, 5),
    estimate_label = "HR"
  )

ggforestplotR documentation built on June 5, 2026, 5:07 p.m.