Flowchart
A flowchart is a type of diagram that represents a workflow or
process. In research we often want to explain how we recruited our
patients, how many that were available from the start, how many that
were excluded and how many were left at the final analysis. The
Gmisc package provides a convenient set of functions
for doing this using the R’s built-in grid package with
some bells and whistles. Below is a simple example that illustrates what
we’re aiming for.
org_cohort <- boxGrob(glue("Stockholm population",
"n = {pop}",
pop = txtInt(1632798),
.sep = "\n"))
eligible <- boxGrob(glue("Eligible",
"n = {pop}",
pop = txtInt(10032),
.sep = "\n"))
included <- boxGrob(glue("Randomized",
"n = {incl}",
incl = txtInt(122),
.sep = "\n"))
grp_a <- boxGrob(glue("Treatment A",
"n = {recr}",
recr = txtInt(43),
.sep = "\n"))
grp_b <- boxGrob(glue("Treatment B",
"n = {recr}",
recr = txtInt(122 - 43 - 30),
.sep = "\n"))
excluded <- boxGrob(glue("Excluded (n = {tot}):",
" - not interested: {uninterested}",
" - contra-indicated: {contra}",
tot = 30,
uninterested = 12,
contra = 30 - 12,
.sep = "\n"),
just = "left")
grid.newpage()
vert <- spreadVertical(org_cohort,
eligible = eligible,
included = included,
grps = list(grp_a, grp_b)) |>
spreadHorizontal(.subelement = "grps")
excluded <- moveBox(excluded,
x = .8,
y = coords(vert$included)$top + distance(vert$eligible, vert$included, half = TRUE, center = FALSE))
for (i in 1:(length(vert) - 1)) {
from <- vert[[i]]
to <- vert[[i + 1]]
connectGrob(vert[[i]], vert[[i + 1]], type = ifelse(is.grob(to), "vert", "N")) |>
print()
}
connectGrob(vert$eligible, excluded, type = "L", label = "Excluded")
# Print boxes
vert
excluded
