GetESS {SubTite}

Determines Prior ESS for fixed values of sigma_alpha^2 and sigmabeta^2

Description

Uses the prior means for the intercept and slope parameters and the number of doses to obtain an approximate prior ESS for the given prior variances. The user should calibrate varint and varbeta with varint>varbeta such that the ESS value is 1.

Usage

GetESS(
  Dose,
  meanmu,
  meanslope,
  MeanInts,
  MeanSlopes,
  VarInt,
  VarSlope,
  phetero
)

Arguments

Dose

Vector containing standardized doses.

meanmu

Prior mean for baseline intercept.

meanslope

Prior mean for baseline slope.

MeanInts

Vector of prior means for the group specific intercept parameters.

MeanSlopes

Vector of prior means for the group specific slope parameters.

VarInt

Prior variance for the intercept parameters.

VarSlope

Prior variance for the slope parameters.

phetero

Prior probability of clustering

Value

Returns the nonlinear regression model whos parameter estimates will be used as prior means for the SubTITE Design.

References

[1] Chapple and Thall (2017), Subgroup-specific dose finding in phase I clinical trials based on time to toxicity allowing adaptive subgroup combination.

Examples

###Specify the prior hypermeans
meanmu=-.5
meanslope=-.05
MeanInts = c(0,-.5,-.1)
MeanSlopes = c(0,.1,0)
Dose=sort(rnorm(5))
VarInt=5
VarSlope=1
phetero=.9
GetESS(Dose,meanmu,meanslope,MeanInts,MeanSlopes,VarInt,VarSlope,phetero)