View source: R/plot_curve_diff.r
plot_curve_diff | R Documentation |
A function to graphically display the difference or ratio between two confounder-adjusted survival curves which where previously estimated using the adjustedsurv
function or between two confounder-adjusted CIFs which where previously estimated using the adjustedcif
function. The user can customize the plot using a variety of options. Internally it uses the ggplot2 package, so additional not implemented features can be added using the standard ggplot2
syntax.
plot_curve_diff(x, group_1=NULL, group_2=NULL,
conf_int=FALSE, conf_level=0.95, type="steps",
times=NULL, max_t=Inf, use_boot=FALSE,
size=0.7, color="black", linetype="solid",
alpha=1, conf_int_alpha=0.4,
points_ci_size=NULL, points_ci_width=NULL,
xlab="Time", ylab=NULL, title=NULL,
subtitle=NULL, gg_theme=ggplot2::theme_classic(),
line_at_ref=TRUE, line_at_ref_size=0.7,
line_at_ref_color="grey", line_at_ref_linetype="dashed",
line_at_ref_alpha=1,
loess_smoother=FALSE, loess_span=0.75,
loess_color=color, loess_size=size,
loess_linetype="dashed", loess_alpha=alpha,
test=NULL, integral_from=0, integral_to=NULL,
p_value=FALSE, integral=FALSE,
interval=FALSE, text_pos_x="left",
text_pos_y="bottom", text_size=3.5,
text_family="serif", text_fontface="italic",
text_color="black", text_alpha=1,
text_digits=3, text_format_p=TRUE,
fill_area=FALSE, area_color="blue", area_alpha=0.4,
fill_only_interval=TRUE,
...)
plot_curve_ratio(x, group_1=NULL, group_2=NULL, conf_int=FALSE,
conf_level=0.95, type="steps", times=NULL,
max_t=Inf, use_boot=FALSE, size=0.7, color="black",
linetype="solid", alpha=1,
conf_int_alpha=0.4, xlab="Time", ylab=NULL,
title=NULL, subtitle=NULL,
gg_theme=ggplot2::theme_classic(),
line_at_ref=TRUE, line_at_ref_size=0.7,
line_at_ref_color="grey",
line_at_ref_linetype="dashed",
line_at_ref_alpha=1, ...)
x |
An |
group_1 |
A single character string specifying one of the levels of the |
group_2 |
Also a single character string specifying one of the levels of |
conf_int |
A logical variable indicating whether the confidence intervals should be drawn. This only works when |
conf_level |
The confidence level that should be used when calculating the confidence intervals. Ignored if |
type |
Must be one of |
times |
An optional numeric vector of points in time at which the difference or ratio should be estimated. If |
max_t |
A number indicating the latest time to which the curve should be extended to. |
use_boot |
Whether to use the bootstrapped estimates to calculate the confidence intervals or not. Can only be used if |
size |
A number controlling the thickness of the curve. |
color |
A string specifying the color of the curve. |
linetype |
A string specifying the linetype of the curve. |
alpha |
A number controlling the transparency level of the curves. |
conf_int_alpha |
A number indicating the level of transparency that should be used when drawing the confidence regions. |
points_ci_size |
Only used when |
points_ci_width |
Only used when |
xlab |
A character string to be used as the X-Axis label of the plot. Defaults to "Time". |
ylab |
A character string to be used as the Y-Axis label of the plot. By default ( |
title |
A character string to be used as the title of the plot. Set to |
subtitle |
A character string to be used as the subtitle of the plot. Set to |
gg_theme |
A |
line_at_ref |
Whether to draw a horizontal line at y = 0 for differences or at y = 1 for ratios or not. |
line_at_ref_size |
The size of the line drawn at the reference value. Ignored if |
line_at_ref_color |
The color of the line drawn at the reference value. Ignored if |
line_at_ref_linetype |
The linetype of the line drawn at the reference value. Ignored if |
line_at_ref_alpha |
The transparency level of the line drawn at the reference value. Ignored if |
loess_smoother |
Whether to draw a LOESS smoother through the difference curves. |
loess_span |
The span of the LOESS smoother. Ignored if |
loess_color |
The color of the LOESS smoother line. Ignored if |
loess_size |
The size of the LOESS smoother line. Ignored if |
loess_linetype |
The linetype of the LOESS smoother line. Ignored if |
loess_alpha |
The transparency level of the LOESS smoother line. Ignored if |
test |
An optional |
integral_from |
A number specifying the left limit of the integral. When |
integral_to |
A number specifying the right limit of the integral. When |
p_value |
Whether to add a p-value to the plot or not. This requires either that the user supplies a previously created |
integral |
Whether to add the integral of the difference in the interval [ |
interval |
Whether to add the interval in which the integral was calculated to the plot as well. |
text_pos_x |
X position of the text. Can be either |
text_pos_y |
Y position of the text. Can be either |
text_digits |
The number of digits to which the p-value and the integral of the difference should be rounded to. |
text_size |
The size of the text. |
text_family |
The family of the text. Defaults to |
text_fontface |
The fontface of the text. Defaults to |
text_color |
The color of the text. Defaults to |
text_alpha |
The transparency level of the text. |
text_format_p |
Whether to format p-values smaller than 0.01 to < 0.01. |
fill_area |
Whether to add color to the area between 0 and the difference. |
area_color |
The color used to fill in the area between 0 and the difference when using |
area_alpha |
The transparency level used to fill in the area between 0 and the difference when using |
fill_only_interval |
Whether only the area corresponding to the interval defined by |
... |
Currently not used. |
This function allows the easy creation of difference / ratio curves. The syntax is exactly the same for both adjusted survival curves and adjusted CIFs. Similarly, the syntax is the same for ratios and for difference curves, although not all options of the difference curve function are available for the ratio curve function. By default it calculates the estimates up to the last point where estimates for both the group_1
curve and the group_2
curve are available.
It currently does not support plotting multiple curves at once, which could be useful when there are more than two treatment groups in variable
. If the user is interested in this, we recommend calling this function multiple times with the desired comparisons and concatenating the individual plots into one plot afterwards using a suitable function such as par
or ggarrange
.
More information on how the differences or ratios and their confidence intervals are calculated can be found in the documentation of the adjusted_curve_diff
function. More information on how the overall p-value and the integral are calculated for differences can be found in the adjusted_curve_test
function.
Returns a ggplot2
object.
Robin Denz
Michael Coory, Karen E. Lamb, and Michael Sorich (2014). "Risk-Difference Curves can be used to Communicate Time-Dependent Effects of Adjuvant Therapies for Early Stage Cancer". In: Journal of Clinical Epidemiology 67, pp. 966-972
Lihui Zhao, Lu Tian, Hajime Uno, Scott D. Solomon, Marc A. Pfeffer, Jerald S. Schindler, and L. J. Wei (2012). "Utilizing the Integrated Difference of Two Survival Functions to Quantify the Treatment Contrast for Designing, Monitoring and Analyzing a Comparative Clinical Study". In: Clinical Trials 9.5, pp. 570-577
adjusted_curve_diff
, adjusted_curve_test
, adjustedsurv
, adjustedcif
, ggplot
, geom_stepribbon
library(adjustedCurves)
library(survival)
if (requireNamespace("ggplot2") & requireNamespace("riskRegression")) {
library(ggplot2)
set.seed(42)
# simulate some data as example
sim_dat <- sim_confounded_surv(n=50, max_t=1.2)
sim_dat$group <- as.factor(sim_dat$group)
# estimate a cox-regression for the outcome
cox_mod <- coxph(Surv(time, event) ~ x1 + x2 + x3 + x4 + x5 + x6 + group,
data=sim_dat, x=TRUE)
# use it to calculate adjusted survival curves with bootstrapping
adjsurv <- adjustedsurv(data=sim_dat,
variable="group",
ev_time="time",
event="event",
method="direct",
outcome_model=cox_mod,
conf_int=TRUE,
bootstrap=TRUE,
n_boot=15) # should be much bigger in reality
# plot the difference with default values
plot_curve_diff(adjsurv)
# plot the ratio with default values
plot_curve_ratio(adjsurv)
# plot with reversed differences
plot_curve_diff(adjsurv, group_1="1", group_2="0")
# plot with confidence intervals
plot_curve_diff(adjsurv, conf_int=TRUE)
plot_curve_ratio(adjsurv, conf_int=TRUE)
# plot using lines instead
plot_curve_diff(adjsurv, conf_int=TRUE, type="lines")
# plot using points instead
plot_curve_diff(adjsurv, conf_int=TRUE, type="points")
# plot using an additional loess smoother
plot_curve_diff(adjsurv, loess_smoother=TRUE)
# plot without the line at reference
plot_curve_diff(adjsurv, line_at_ref=FALSE)
plot_curve_ratio(adjsurv, line_at_ref=FALSE)
# plot with some custom parameters
plot_curve_diff(adjsurv, conf_int=TRUE, color="blue", linetype="dotted",
alpha=0.8, line_at_ref_size=1.1, line_at_ref_color="red",
loess_smoother=TRUE, loess_span=0.55)
# adding a p-value for a difference test in the interval [0, 0.75]
plot_curve_diff(adjsurv, conf_int=TRUE, p_value=TRUE, integral_from=0,
integral_to=0.75, integral=TRUE)
# adding a p-value for a difference test in the interval [0, 0.75],
# and also showing that integral visually in the plot
plot_curve_diff(adjsurv, conf_int=FALSE, p_value=TRUE, integral_from=0,
integral_to=0.75, integral=TRUE, fill_area=TRUE,
interval=TRUE)
}
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