plotTreatPredJointSurro {frailtypack}

Plot of the prediction of the treatment effect on the true endpoint and the STE

Description

Plot the prediction of the treatment effect on the true endpoint based on the observed treatment effect on the surrogate endpoint, with the prediction interval: results from the one-step Joint surrogate model for evaluating a canditate surrogate endpoint. The graphic also includes vertical lines that cut the x axis to the values of ste. A hatched rectagle/zone indicates the values of \beta_S that predict a non zeto \beta_T, according to the number of value for STE and the shape of the upper confidence limit for the prediction model.

Usage

plotTreatPredJointSurro(
  object,
  from = -3,
  to = 2,
  type = "Coef",
  var.used = "error.estim",
  alpha. = 0.05,
  n = 1000,
  lty = 2,
  d = 3,
  colCI = "blue",
  xlab = "beta.S",
  ylab = "beta.T.predict",
  pred.int.use = "up",
  main = NULL,
  add.accept.area.betaS = TRUE,
  ybottom = -0.05,
  ytop = 0.05,
  density = 20,
  angle = 45,
  legend.show = TRUE,
  leg.x = NULL,
  leg.y = 2,
  legend = c("Prediction model", "95% prediction Interval", "Beta.S for nonzero beta.T",
    "STE"),
  leg.text.col = "black",
  leg.lty = c(1, 2, 4, NA),
  leg.pch = c(NA, NA, 7, 1),
  leg.bg = "white",
  leg.bty = "n",
  leg.cex = 0.85,
  ...
)

Arguments

object

An object inheriting from jointSurroPenal class (output from calling the function jointSurroPenal ).

from

The range (with to) over which the function will be plotted. The default is from -2 to 2

to

The range (with from) over which the function will be plotted. The default is from -2 to 2

type

The type of graphic, "Coef" for the log HR or "HR" for hazard ratio. If set to HR, the arguments from and to must take positive values. The default is "Coef".

var.used

This argument can take two values. The first one is "error.estim" and indicates if the prediction error take into account the estimation error of the estimates of the parameters. If the estimates are supposed to be known or if the dataset includes a high number of trials with a high number of subject per trial, value No.error can be used. The default is error.estim (highly recommended).

alpha.

The confidence level for the prediction interval. The default is 0.05

n

An integer that indicates the number of values for \beta_S. The default is 1000.

lty

The line type. Line types can either be specified as an integer (0=blank, 1=solid (default), 2=dashed, 3=dotted, 4=dotdash, 5=longdash, 6=twodash) or as one of the character strings "blank", "solid", "dashed", "dotted", "dotdash", "longdash", or "twodash", where "blank" uses "invisible lines" (i.e., does not draw them). The default is 2.

d

The desired number of digits after the decimal point for parameters and confidence intervals. Default of 3 digits is used.

colCI

The color used to display the confidence interval.

xlab

A title for the x axis.

ylab

A title for the y axis.

pred.int.use

A character string that indicates the bound of the prediction interval to use to compute the STE. Possible values are up for the upper bound (the default) or lw for the lower bound. up when we have a protective treatment effect and lw when we have a deleterious treatment effect.

main

Title of the graphics

add.accept.area.betaS

A boolean that indicates if the plot should add acceptance area for \beta_S that predict a nonzero \beta_T. The default is TRUE

ybottom

A scalar for the left y bottom position of the rectangle on the x-axis associated with acceptable value for \beta_S to predict a non zero \beta_T. The default is -0.05.

ytop

A scalar for the top right y position of the rectangle on the x-axis associated with acceptable value for \beta_S to predict a non zero \beta_T. The default is 0.05.

density

The density of shading lines, in lines per inch. The default value of 'NULL' means that no shading lines are drawn. A zero value of 'density' means no shading lines whereas negative values (and 'NA') suppress shading (and so allow color filling). The default is 20

angle

Angle (in degrees) of the shading lines. The default is 45

legend.show

A boolean that indicates if the legend should be displayed

leg.x

The x co-ordinate to be used to position the legend.

leg.y

The y co-ordinate to be used to position the legend. The default is 4

legend

A character or expression vector of length >= 1 to appear in the legend

leg.text.col

The color used for the legend text. The default is black.

leg.lty

The line type, width and color for the legend box (if bty = "o").

leg.pch

= The plotting symbols appearing in the legend, as numeric vector or a vector of 1-character strings (see points). Unlike points, this can all be specified as a single multi-character string. Must be specified for symbol drawing.

leg.bg

The background color for the legend box. (Note that this is only used if bty != "n".)

leg.bty

The type of box to be drawn around the legend. The allowed values are "o" (the default) and "n".

leg.cex

Character expansion factor relative to current par("cex"). Used for text as defined in legend.

...

other unused arguments

Value

For a considered treatment effects on the surrogate enpoint, plot the associated treatment effects on the true endpoint predicted from the joint surrogate model with the prediction interval.

Author(s)

Casimir Ledoux Sofeu [e-mail], [e-mail] and Virginie Rondeau [e-mail]

References

Burzykowski T, Buyse M (2006). "Surrogate threshold effect: an alternative measure for meta-analytic surrogate endpoint validation." Pharmaceutical Statistics, 5(3), 173-186.ISSN 1539-1612.

Sofeu, C. L. and Rondeau, V. (2020). How to use frailtypack for validating failure-time surrogate endpoints using individual patient data from meta-analyses of randomized controlled trials. PLOS ONE; 15, 1-25.

See Also

jointSurroPenal, jointSurroCopPenal, predict.jointSurroPenal

Examples

## Not run: 


###--- Joint surrogate model ---###
###---evaluation of surrogate endpoints---###

data(dataOvarian)
joint.surro.ovar <- jointSurroPenal(data = dataOvarian, n.knots = 8, 
                init.kappa = c(2000,1000), indicator.alpha = 0, 
                nb.mc = 200, scale = 1/365)

## "HR"
plotTreatPredJointSurro(joint.surro.ovar, from = 0, to = 4, 
                type = "HR", lty = 2, leg.y = 13)
                
## or without acceptance area for betaS:
plotTreatPredJointSurro(joint.surro.ovar, from = 0, to = 4, 
                type = "HR", lty = 2, leg.y = 13, 
                add.accept.area.betaS = FALSE)
             
## "log HR"
plotTreatPredJointSurro(joint.surro.ovar, from = -2, to = 2, 
                type = "Coef", lty = 2, leg.y = 3.5)
                
### For a value of ste greater than 0 (HR > 1), which induces deleterious
### treatment effet, argument "pred.int.use" can be set to "lw"  

plotTreatPredJointSurro(joint.surro.ovar, from = 0, to = 2, 
                type = "HR", lty = 2, leg.y = 4,
                pred.int.use = "lw")


## End(Not run)