BCEA (version 1.0)

ib.plot: Incremental Benefit distribution plot

Description

Plots the distribution of the Incremental Benefit for a given value of the willingness to pay threshold, k

Usage

ib.plot(he, comparison = NULL, wtp = 25000, bw = nbw, n = 512, xlim = NULL)

Arguments

he

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

comparison

In the case of multiple interventions, specifies the one to be used in comparison with the reference. Default value of NULL forces R to consider the first non-reference intervention as the comparator

wtp

The value of the willingness to pay threshold. Default value at 25000

bw

Identifies the smoothing bandwith used to construct the kernel estimation of the IB density.

n

The number of equally spaced points at which the density is to be estimated

xlim

The limits of the plot on the x-axis

Value

• The function produces a plot of the distribution of the Incremental Benefit for a given value of the willingness to pay parameter. The dashed area indicates the positive part of the distribution (ie when the reference is more cost-effective than the comparator)

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, ib.plot, ceplane.plot

Examples

# See Baio G., Dawid A.P. (2011) for a detailed description of the 
# Bayesian model and economic problem
#
# Load the processed results of the MCMC simulation model
data(Vaccine)
# 
# Runs the health economic evaluation using BCEA
m <- bcea(e=e,c=c,          # defines the variables of 
                            #  effectiveness and cost
      ref=2,                # selects the 2nd row of (e,c) 
                            #  as containing the reference intervention
      interventions=treats, # defines the labels to be associated 
                            #  with each intervention
      Kmax=50000            # maximum value possible for the willingness 
                            #  to pay threshold; implies that k is chosen 
                            #  in a grid from the interval (0,Kmax)
)
# 
# Plots the distribution of the Incremental Benefit
ib.plot(m,        # uses the results of the economic evalaution 
                  #  (a "bcea" object)
    comparison=1, # if more than 2 interventions, selects the 
                  #  pairwise comparison 
    wtp=25000     # selects the relevant willingness 
                  #  to pay (default: 25,000) 
)