## [1] "LogisticKadaneBetaGamma"
A logistic model using the parameterisation of Kadane (1980) will describe the relationship between dose and toxicity, using a Beta distribution as the prior for ρ0 and a Gamma distribution as the prior for γ.
Let the minimum (xmin) and maximum (xmax) doses be 0.00 and 7.00.
Further, let θ denote the target toxicity rate and ρ0 = p(DLT | D = xmin).
Let γ be the dose with target toxicity rate θ, so that p(DLT | D = γ) = θ = 0.3.
Using this parameterisation, standard logistic regression model has slope \[ \frac{\gamma \text{logit}(\rho_0) - x_{min} \text{logit}(\theta)}{\gamma - x_{min}} \] and intercept \[ \frac{\text{logit}(\theta) - logit(\rho_0)}{\gamma - x_{min}} \] The priors for Γ and Ρ0 are \[ \Gamma \sim U( 0.56, 0.12) \] and, independently, \[ \mathrm{P}_0 \sim Beta(1, 19) \]
Note that xmin and xmax need not be equal to
the smallest and largest values in the doseGrid slot of the
corresponding Data object.