Set Table Footnotes

Sets one or more footnote lines displayed below the table body. Each argument in ... produces one footnote line. Calling fr_footnotes() again replaces all previously set footnotes.

Footnotes support inline {fr_*()} markup, including fr_super() for superscript footnote labels.

Usage

fr_footnotes(
  spec,
  ...,
  .align = "left",
  .placement = "every",
  .font_size = NULL,
  .separator = FALSE
)

Arguments

spec

An fr_spec object from fr_table().

...

One or more footnotes. Each may be:

A character scalar — the footnote text.
A list. The first element is the footnote text (can be unnamed). Optionally include align, placement, font_size to override formatting.

.align

Default alignment. "left" (default) is standard for regulatory submissions. Override per line via the list form.

.placement

When to print footnotes. "every" (default) repeats footnotes on every page; "last" prints them only on the final page. Override per footnote via the list form.

.font_size

Default font size in points. NULL inherits from page.

.separator

Logical. Whether to draw a horizontal separator rule above the footnote block. Default FALSE.

Value

A modified fr_spec. Footnotes are stored in spec$meta$footnotes.

Regulatory conventions

ICH E3 and common pharma submission standards specify:

Labelling:

Footnote labels use lower-case letters in square brackets: [a], [b], [c]. Do not use numeric labels — [1], [2] are reserved for literature references.
Do not begin the footnote section with the word "Note" or "Notes:".

Layout:

Each footnote on its own line, left-aligned, same or smaller font than the table body.
RTF/SAS submissions: limit to 8 footnotes per table for full compatibility with standard TLG macro footnote slots.

Ordering:

[a], [b], … content footnotes first (in the order symbols appear reading left-to-right, top-to-bottom through the table).
Abbreviation expansion line last (e.g. "AE = Adverse Event; FAS = Full Analysis Set; SD = Standard Deviation.").
Source / data-cut note on the final page only (placement = "last").

Common regulatory footnote patterns:

Percentage denominator: "[a] Percentages are based on N in the column header." — required whenever n (%) columns appear.
MedDRA coding: "[a] Coded using MedDRA Version XX.X." — for AE, medical history, and prior/concomitant medication tables.
Subject counting: "[a] A subject is counted only once for multiple events within the same System Organ Class or Preferred Term." — AE tables where events > subjects is possible.
Dagger symbol: use {fr_dagger()} and {fr_ddagger()} markup for treatment-related or serious AE markers.

Spacing

By default, one blank line is inserted between the last body row and the first footnote. Control this with fr_spacing():

spec |> fr_spacing(footnotes_before = 0L)   # no gap
spec |> fr_spacing(footnotes_before = 2L)   # two blank lines

This can also be set in _arframe.yml:

spacing:
  footnotes_before: 1

Tips

Use fr_super() for superscript footnote markers inside cell values: "{fr_super('a')} Value with footnote". The matching footnote line should begin with "[a] ...".
Set .separator = FALSE when the table ends with a bottom rule that already visually separates the footnotes.
placement = "last" for the source note prevents it repeating on every continuation page. Note: this only works in PDF output. RTF has no mechanism for last-page-only footer content ({\footer} repeats on every page). In RTF, all footnotes appear on every page regardless of placement. A warning is emitted when rendering to RTF with placement = "last" footnotes.

Examples

## ── Demographics table: standard footnote set ─────────────────────────────

# Correct order: [a][b] content footnotes, abbreviations last, source final page
tbl_demog |>
  fr_table() |>
  fr_footnotes(
    "[a] Percentages are based on N in the column header.",
    "[b] P-value from two-sample t-test (continuous) or chi-squared (categorical).",
    "FAS = Full Analysis Set; SD = Standard Deviation.",
    list("Source: ADSL; data cut 31DEC2024.", placement = "last")
  )
#> 
#> ── fr_spec: Table 
#> Data: 28 rows x 6 columns
#> Page: landscape letter, 9pt Courier New
#> Header: valign=bottom
#> Footnotes (4):
#> 1. [left] "[a] Percentages are based on N in the column header."
#> 2. [left] "[b] P-value from two-sample t-test (continuous) or chi-sq..."
#> 3. [left] "FAS = Full Analysis Set; SD = Standard Deviation."
#> 4. [left [last]] "Source: ADSL; data cut 31DEC2024."

## ── AE table: MedDRA + subject-counting + source footnotes ───────────────

tbl_ae_soc |>
  fr_table() |>
  fr_footnotes(
    "[a] Coded using MedDRA Version 27.1.",
    paste0("[b] A subject is counted only once for multiple events within ",
           "the same System Organ Class or Preferred Term."),
    "[c] Percentages are based on N in the column header.",
    paste0("AE = Adverse Event; PT = Preferred Term; ",
           "SOC = System Organ Class; TEAE = Treatment-Emergent AE."),
    list("Source: ADAE; data cut 31DEC2024.", placement = "last")
  )
#> 
#> ── fr_spec: Table 
#> Data: 96 rows x 7 columns
#> Page: landscape letter, 9pt Courier New
#> Header: valign=bottom
#> Footnotes (5):
#> 1. [left] "[a] Coded using MedDRA Version 27.1."
#> 2. [left] "[b] A subject is counted only once for multiple events wi..."
#> 3. [left] "[c] Percentages are based on N in the column header."
#> 4. [left] "AE = Adverse Event; PT = Preferred Term; SOC = System Org..."
#> 5. [left [last]] "Source: ADAE; data cut 31DEC2024."

## ── Source note on last page only ────────────────────────────────────────

tbl_demog |>
  fr_table() |>
  fr_footnotes(
    "[a] Percentages based on N in column header.",
    list("Source: ADSL; data cut 31DEC2024.", placement = "last")
  )
#> 
#> ── fr_spec: Table 
#> Data: 28 rows x 6 columns
#> Page: landscape letter, 9pt Courier New
#> Header: valign=bottom
#> Footnotes (2):
#> 1. [left] "[a] Percentages based on N in column header."
#> 2. [left [last]] "Source: ADSL; data cut 31DEC2024."

## ── Inline markup: dagger and double-dagger symbols ──────────────────────

tbl_ae_soc |>
  fr_table() |>
  fr_footnotes(
    "{fr_dagger()} Treatment-related adverse events.",
    "{fr_ddagger()} Serious adverse events."
  )
#> 
#> ── fr_spec: Table 
#> Data: 96 rows x 7 columns
#> Page: landscape letter, 9pt Courier New
#> Header: valign=bottom
#> Footnotes (2):
#> 1. [left] "† Treatment-related adverse events."
#> 2. [left] "‡ Serious adverse events."

## ── Per-line font size override ───────────────────────────────────────────

tbl_demog |>
  fr_table() |>
  fr_footnotes(
    "[a] Percentages based on N in column header.",
    list("Source: ADSL.", font_size = 7)
  )
#> 
#> ── fr_spec: Table 
#> Data: 28 rows x 6 columns
#> Page: landscape letter, 9pt Courier New
#> Header: valign=bottom
#> Footnotes (2):
#> 1. [left] "[a] Percentages based on N in column header."
#> 2. [left] "Source: ADSL."

## ── No separator rule ────────────────────────────────────────────────────

tbl_demog |>
  fr_table() |>
  fr_hlines("hsides") |>
  fr_footnotes(
    "[a] Percentages based on N in column header.",
    .separator = FALSE
  )
#> 
#> ── fr_spec: Table 
#> Data: 28 rows x 6 columns
#> Page: landscape letter, 9pt Courier New
#> Header: valign=bottom
#> Rules: 2 hline(s)
#> Footnotes (1):
#> 1. [left] "[a] Percentages based on N in column header."

## ── Right-aligned footnotes ───────────────────────────────────────────────

tbl_demog |>
  fr_table() |>
  fr_footnotes(
    "[a] Percentages based on N in column header.",
    .align = "right"
  )
#> 
#> ── fr_spec: Table 
#> Data: 28 rows x 6 columns
#> Page: landscape letter, 9pt Courier New
#> Header: valign=bottom
#> Footnotes (1):
#> 1. [right] "[a] Percentages based on N in column header."

## ── Clear all footnotes ───────────────────────────────────────────────────

spec <- tbl_demog |> fr_table() |> fr_footnotes("[a] Old footnote.")
spec <- spec |> fr_footnotes()  # removes all footnotes