getPriorParameters {bhmbasket}  R Documentation 
getPriorParameters
Description
This function provides default prior parameters for the analysis methods
that can be used in performAnalyses
.
Usage
getPriorParameters(
method_names,
target_rates,
n_worth = 1,
tau_scale = 1,
w_j = 0.5
)
Arguments
method_names 
A vector of strings for the names of the methods to be used.
Available methods: 
target_rates 
A vector of numerics in 
n_worth 
An integer for the number of subjects the variability of the prior should reflect
response rate scale, Default: 
tau_scale 
A numeric for the scale parameter of the Halfnormal distribution of 
w_j 
A numeric in 
Details
Regarding the default prior parameters for "berry"
, "exnex"
, and "exnex_adj"
:

"berry"
: The mean of\mu
is set to0
. Its variance is calculated as proposed in "Robust exchangeability designs for early phase clinical trials with multiple strata" (Neuenschwander et al. (2016)) with regard ton_worth
. The scale parameter of\tau
is set totau_scale
. 
"exnex"
: The weight of the Ex component is set tow_j
. For the Ex component: The target rate that results in the greatest variance is determined. The mean of\mu
is set to that target rate. The variance of\mu
is calculated as proposed in "Robust exchangeability designs for early phase clinical trials with multiple strata" (Neuenschwander et al. (2016)) with regard ton_worth
. The scale parameter of\tau
is set totau_scale
. For the Nex components: The means of\mu_j
are set to the respective target rates. The variances of\tau_j
are calculated as proposed in "Robust exchangeability designs for early phase clinical trials with multiple strata" (Neuenschwander et al. (2016)) with regard ton_worth
, see alsogetMuVar
. 
"exnex_adj"
: The weight of the Ex component is set tow_j
. For the Ex component: The target rate that results in the greatest variance is determined. The mean of\mu
is set to0
. The variance of\mu
is calculated as proposed in "Robust exchangeability designs for early phase clinical trials with multiple strata" (Neuenschwander et al. (2016)) with regard ton_worth
, see alsogetMuVar
. The scale parameter of\tau
is set totau_scale
. For the Nex components: The means of\mu_j
are set to the0
. The variances of\tau_j
are calculated as proposed in "Robust exchangeability designs for early phase clinical trials with multiple strata" (Neuenschwander et al. (2016)) with regard ton_worth
, see alsogetMuVar
. 
"pooled"
: The target rate that results in the greatest variance is determined. The scale parameter\alpha
is set to that target rate timesn_worth
. The scale parameter\beta
is set to 1  that target rate timesn_worth
. 
"stratified"
: The scale parameters\alpha_j
are set totarget_rates * n_worth
. The scale parameters\beta_j
are set to(1  target_rates) * n_worth
.
Value
A list with prior parameters of class prior_parameters_list
Author(s)
Stephan Wojciekowski
References
Berry, Scott M., et al. "Bayesian hierarchical modeling of patient subpopulations: efficient designs of phase II oncology clinical trials." Clinical Trials 10.5 (2013): 720734.
Neuenschwander, Beat, et al. "Robust exchangeability designs for early phase clinical trials with multiple strata." Pharmaceutical statistics 15.2 (2016): 123134.
See Also
performAnalyses
setPriorParametersBerry
setPriorParametersExNex
setPriorParametersExNexAdj
setPriorParametersPooled
setPriorParametersStratified
combinePriorParameters
getMuVar
Examples
prior_parameters_list < getPriorParameters(
method_names = c("berry", "exnex", "exnex_adj", "pooled", "stratified"),
target_rates = c(0.1, 0.2, 0.3))