ceef.plot {BCEA}R Documentation

Cost-Effectiveness Efficiency Frontier (CEAF) plot

Description

Produces a plot of the Cost-Effectiveness Efficiency Frontier (CEEF)

Usage

ceef.plot(he, comparators = NULL, pos = c(1, 1), 
start.from.origins = TRUE, threshold = NULL, flip = FALSE, 
dominance = TRUE, relative = FALSE, print.summary = TRUE, 
graph = c("base", "ggplot2"), ...)

Arguments

he

A bcea object containing the results of the Bayesian modelling and the economic evaluation. The list needs to include the e and c matrices used to generate the object; see Details.

comparators

Vector specifying the comparators to be included in the frontier analysis. Must be of length > 1. Default as NULL includes all the available comparators.

pos

Parameter to set the position of the legend. Can be given in form of a string (bottom|top)(right|left) for base graphics and bottom, top, left or right for ggplot2. It can be a two-elements vector, which specifies the relative position on the x and y axis respectively, or alternatively it can be in form of a logical variable, with FALSE indicating to use the default position and TRUE to place it on the bottom of the plot. Default value is c(1,1), that is the topright corner inside the plot area.

start.from.origins

Logical. Should the frontier start from the origins of the axes? The argument is reset to FALSE if the average effectiveness and/or costs of at least one comparator are negative.

threshold

Specifies if the efficiency should be defined based on a willingness-to-pay threshold value. If set to NULL (the default), no conditions are included on the slope increase. If a positive value is passed as argument, to be efficient an intervention also requires to have an ICER for the comparison versus the last efficient strategy not greater than the specified threshold value. A negative value will be ignored with a warning.

flip

Logical. Should the axes of the plane be inverted?

dominance

Logical. Should the dominance regions be included in the plot?

relative

Logical. Should the plot display the absolute measures (the default as FALSE) or the differential outcomes versus the reference comparator?

print.summary

Logical. Should the efficiency frontier summary be printed along with the graph? See Details for additional information.

graph

A string used to select the graphical engine to use for plotting. Should (partial-)match the two options "base" or "ggplot2". Default value is "base".

...

If graph="ggplot2" and a named theme object is supplied, it will be added to the ggplot object. Ignored if graph="base". Setting the optional argument include.ICER to TRUE will print the ICERs in the summary tables, if produced.

Details

The bcea objects did not include the generating e and c matrices in BCEA versions <2.1-0. This function is not compatible with objects created with previous versions. The matrices can be appended to bcea objects obtained using previous versions, making sure that the class of the object remains unaltered.

The argument print.summary allows for printing a brief summary of the efficiency frontier, with default to TRUE. Two tables are plotted, one for the interventions included in the frontier and one for the dominated interventions. The average costs and clinical benefits are included for each intervention. The frontier table includes the slope for the increase in the frontier and the non-frontier table displays the dominance type of each dominated intervention. Please note that the slopes are defined as the increment in the costs for a unit increment in the benefits even if flip = TRUE for consistency with the ICER definition. The angle of increase is in radians and depends on the definition of the axes, i.e. on the value given to the flip argument.

If the argument relative is set to TRUE, the graph will not display the absolute measures of costs and benefits. Instead the axes will represent differential costs and benefits compared to the reference intervention (indexed by ref in the bcea function).

Value

ceplane

A ggplot object containing the plot. Returned only if graph="ggplot2".

The function produces a plot of the cost-effectiveness efficiency frontier. The dots show the simulated values for the intervention-specific distributions of the effectiveness and costs. The circles indicate the average of each bivariate distribution, with the numbers referring to each included intervention. The numbers inside the circles are black if the intervention is included in the frontier and grey otherwise. If the option dominance is set to TRUE, the dominance regions are plotted, indicating the areas of dominance. Interventions in the areas between the dominance region and the frontier are in a situation of extended dominance.

Author(s)

Andrea Berardi, Gianluca Baio

References

Baio G. (2012). Bayesian Methods in Health Economics. CRC/Chapman Hall, London.

IQWIG (2009). General methods for the Assessment of the Relation of Benefits to Cost, Version 1.0. IQWIG, November 2009.

See Also

bcea

Examples

### create the bcea object m for the smoking cessation example
data(Smoking)
m <- bcea(e,c,ref=4,Kmax=500,interventions=treats)
### produce the plot
ceef.plot(m,graph="base")

### tweak the options
ceef.plot(m,flip=TRUE,dominance=FALSE,start.from.origins=FALSE,
          print.summary=FALSE,graph="base")
### or use ggplot2 instead
if(require(ggplot2)){
ceef.plot(m,dominance=TRUE,start.from.origins=FALSE,pos=TRUE,
          print.summary=FALSE,graph="ggplot2")
}


[Package BCEA version 2.3-1.1 Index]