confIntArea {survCurve}

Adds a confident interval area of a survival model to a plot.

Description

This function adds the confident interval area of one group (strata) of a survfit object to an existing plot. For competitive risk models, it draws the confidence interval of one group and one event; the event-number needs to be specified. If two overlapping confidence intervals are drawn (by two function calls) in one plot, the use of transparent color is recommended, for example "adjustcolor("red",0.1).

Usage

confIntArea(x, group, event, col = "grey", invert = FALSE)

Arguments

x

A survfit (survival-package) or a Cuminc (mstate-package) object.

group

Number of the group (=strata) of which the confidence interval should be plotted. If the survfit-object has only one strata, this parameter can be omitted.

event

If the model-object is a multistate-model, the number of the event-type needs to be specified.

col

Color of the confident interval area. Default is "grey". A transparent value is recommended, for example "adjustcolor("red",0.1).

invert

Inverts the area if TRUE, default is FALSE.

Value

Draws an area for the confidence interval.

Examples

  require(survival)
  aml_model <- with(aml, survfit(Surv(time, status)~x))
  col1 <- adjustcolor("red",0.2); col2 <- adjustcolor("blue",0.2)
  survPlot(xmax=50, space.nrAtRisk=0.32)
  confIntArea(aml_model, col=col1, group=1)
  confIntArea(aml_model, col=col2, group=2)
  survCurve(aml_model, group=1)
  survCurve(aml_model, group=2, lty=2)
  nrAtRisk(aml_model, group=1, y=-0.17, bgcol.flag=col1, label="maintain")
  nrAtRisk(aml_model, group=2, y=-0.24, bgcol.flag=col2, lty.flag=2, label="non-maint.")