Kaplan-Meier plot function

Kaplan-Meier plot using ggplot2.

km_plot(
  survfit_obj,
  make_step = NULL,
  first_point = 1,
  one_level = FALSE,
  y_lim = NULL,
  percent_accuracy = 1,
  y_breaks = 5,
  x_lim = NULL,
  x_breaks = 1,
  n_points = NULL,
  n_risk_break = 50,
  title = NULL,
  subtitle = NULL,
  title_size = 14,
  subtitle_size = 10,
  title_margin = 1,
  y_lab = NULL,
  x_lab = NULL,
  background_color = "moccasin",
  panel_grid_color = "grey",
  panel_grid_size = 0.3,
  axis_size = 0.3,
  text_size = 8,
  line_size = 0.5,
  show_ci = TRUE,
  ribbon_ci = TRUE,
  ribbon_alpha = 0.5,
  ci_line_size = 0.2,
  line_colors = c("#377EB8", "#E41A1C", "#4DAF4A", "#984EA3", "#FF7F00", "#FFFF33",
    "#A65628", "#F781BF"),
  legend_pos = c(0, 0),
  legend_labels = ggplot2::waiver(),
  label_breaks = ggplot2::waiver(),
  legend_key_height_mult = 1
)

Arguments

survfit_obj	Object returned from survfit function in survival package. Also works with data frame if year and surv variable exist. lower and upper variable needed if show_ci = TRUE. Specify strata variable needed if several curves wanted.
make_step	If TRUE, step data will be created.
first_point	If make_step = TRUE, first_point for KM is 1 and for competing risk 0.
one_level	Boolean indicating if there is only one level in the strata.
y_lim	Limit on y-axis.
percent_accuracy	Set accuracy for percent_format.
y_breaks	Length between each break on y-axis.
x_lim	Limit on x-axis.
x_breaks	Length between each break on x-axis.
n_points	Number of points to be plotted, useful to change if file is large because of too many points!
n_risk_break	Minimum number at risk to include
title	Plot title, NULL for no title.
subtitle	Small text under title, NULL for no subtitle.
title_size	Text size of title in pt.
subtitle_size	Text size of subtitle in pt.
title_margin	Space between title and subtitle in pt.
y_lab	Y-axis label.
x_lab	X-axis label.
background_color	Color of the panel background.
panel_grid_color	Color of the panel grid lines.
panel_grid_size	Size of the panel grid lines in plot, useful to change if large dpi!
axis_size	Size of the axis lines, useful to change if large dpi!
text_size	Size of the text in pt.
line_size	Size of the head lines.
show_ci	If TRUE, show confidence interval lines.
ribbon_ci	Show confidence interval
ribbon_alpha	Degree of transparency for confidence interval
ci_line_size	Size of the confidence interval lines.
line_colors	Color of the different curves.
legend_pos	Position of the legend in plot.
legend_labels	Label for each legend key, default order as they appear in names(survfit_obj$strata).
label_breaks	Order of the legend keys.
legend_key_height_mult	Increase space between legend keys with a multiple.

Value

ggplot object containing Kaplan-Meier plot.

Examples

# KM-plot with 2 levels
survfit_obj <-
  survival::survfit(survival::Surv(time/365.24, status) ~ sex,
  data = survival::colon
)
km_plot(survfit_obj, y_lim = c(40,100), y_breaks = 10, x_lim = c(0,9))

# KM-plot with 6 levels
survfit_obj <-
  survival::survfit(survival::Surv(time/365.24, status) ~ sex + differ,
  data = survival::colon
)
km_plot(survfit_obj, y_lim = c(30,100), y_breaks = 10,
x_lim = c(0,9), line_colors =
  c('dodgerblue', 'red', 'green', 'black', 'yellow', 'chocolate'))