Combine a List of Survfit Objects on the Same Plot — ggsurvplot

Combine multiple survfit objects on the same plot. For example, one might wish to plot progression free survival and overall survival on the same graph (and also stratified by treatment assignment). ggsurvplot_combine() provides an extension to the ggsurvplot() function for doing that.

Usage

ggsurvplot_combine(
  fit,
  data,
  risk.table = FALSE,
  risk.table.pos = c("out", "in"),
  cumevents = FALSE,
  cumcensor = FALSE,
  tables.col = "black",
  tables.y.text = TRUE,
  tables.y.text.col = TRUE,
  ggtheme = theme_survminer(),
  tables.theme = ggtheme,
  keep.data = FALSE,
  risk.table.y.text = tables.y.text,
  ...
)

Arguments

fit

a named list of survfit objects.

data

the data frame used to compute survival curves.

risk.table

Allowed values include:

TRUE or FALSE specifying whether to show or not the risk table. Default is FALSE.
"absolute" or "percentage". Shows the absolute number and the percentage of subjects at risk by time, respectively.
"abs_pct" to show both absolute number and percentage.
"nrisk_cumcensor" and "nrisk_cumevents". Show the number at risk and, the cumulative number of censoring and events, respectively.

risk.table.pos

character vector specifying the risk table position. Allowed options are one of c("out", "in") indicating 'outside' or 'inside' the main plot, respectively. Default value is "out".

cumevents

logical value specifying whether to show or not the table of the cumulative number of events. Default is FALSE.

cumcensor

logical value specifying whether to show or not the table of the cumulative number of censoring. Default is FALSE.

tables.col

color to be used for all tables under the main plot. Default value is "black". If you want to color by strata (i.e. groups), use tables.col = "strata".

tables.y.text

logical. Default is TRUE. If FALSE, the y axis tick labels of tables will be hidden.

tables.y.text.col

logical. Default value is FALSE. If TRUE, tables tick labels will be colored by strata.

ggtheme

function, ggplot2 theme name. Default value is theme_survminer. Allowed values include ggplot2 official themes: see theme.

tables.theme

function, ggplot2 theme name. Default value is theme_survminer. Allowed values include ggplot2 official themes: see theme. Note that, tables.theme is incremental to ggtheme.

keep.data

logical value specifying whether the plot data frame should be kept in the result. Setting these to FALSE (default) can give much smaller results and hence even save memory allocation time.

risk.table.y.text

logical. Default is TRUE. If FALSE, risk table y axis tick labels will be hidden.

...

other arguments to pass to the ggsurvplot() function.

Examples

library(survival)
# Create a demo data set
#::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 set.seed(123)
 demo.data <- data.frame(
   os.time = colon$time,
   os.status = colon$status,
   pfs.time = sample(colon$time),
   pfs.status = colon$status,
   sex = colon$sex, rx = colon$rx, adhere = colon$adhere
 )

# Ex1: Combine null models
#::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 # Fit
 pfs <- survfit( Surv(pfs.time, pfs.status) ~ 1, data = demo.data)
 os <- survfit( Surv(os.time, os.status) ~ 1, data = demo.data)
 # Combine on the same plot
 fit <- list(PFS = pfs, OS = os)
 ggsurvplot_combine(fit, demo.data)


# Combine survival curves stratified by treatment assignment rx
#::::::::::::::::::::::::::::::::::::::::::::::::::::::::
# Fit
pfs <- survfit( Surv(pfs.time, pfs.status) ~ rx, data = demo.data)
os <- survfit( Surv(os.time, os.status) ~ rx, data = demo.data)
# Combine on the same plot
fit <- list(PFS = pfs, OS = os)
ggsurvplot_combine(fit, demo.data)