BCEA (version 2.2-3)

contour.bcea: Contour method for objects in the class bcea

Description

Produces a scatterplot of the cost-effectiveness plane, with a contour-plot of the bivariate density of the differentials of cost (y-axis) and effectiveness (x-axis)

Usage

"contour"(x, comparison = 1, scale = 0.5, nlevels = 4, levels = NULL,  pos = c(1,0), xlim=NULL, ylim=NULL, graph=c("base","ggplot2"), ...)

Arguments

x

A bcea object containing the results of the Bayesian modelling and the economic evaluation

comparison

In case of more than 2 interventions being analysed, selects which plot should be made. By default the first comparison among the possible ones will be plotted. If graph="ggplot2" any subset of the possible comparisons can be selected, and comparison=NULL will yield a plot of all the possible comparisons together.

scale

Scales the plot as a function of the observed standard deviation.

levels

Numeric vector of levels at which to draw contour lines. Will be ignored using graph="ggplot2".

nlevels

Number of levels to be plotted in the contour.

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 the legend on the bottom of the plot. Default value is c(1,0), that is the bottomright corner inside the plot area.

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".

xlim

The range of the plot along the x-axis. If NULL (default) it is determined by the range of the simulated values for delta.e

ylim

The range of the plot along the y-axis. If NULL (default) it is determined by the range of the simulated values for delta.c

...

Additional arguments to 'plot.window', 'title', 'Axis' and 'box', typically graphical parameters such as 'cex.axis'. Will be ignored if graph="ggplot2".

Value

ceplane

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

Plots the cost-effectiveness plane with a scatterplot of all the simulated values from the (posterior) bivariate distribution of (Delta_e,Delta_c), the differentials of effectiveness and costs; superimposes a contour of the distribution and prints the estimated value of the probability of each quadrant (combination of positive/negative values for both Delta_e and Delta_c)

References

Baio, G., Dawid, A. P. (2011). Probabilistic Sensitivity Analysis in Health Economics. Statistical Methods in Medical Research doi:10.1177/0962280211419832.

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

See Also

bcea, ceplane.plot, contour2