IncrementsHSRBeta

IncrementsHSRBeta is a class for limiting further increments using a Hard Safety Rule based on the Bin-Beta model. Increment control is based on the number of observed DLTs and number of subjects at each dose level. The probability of toxicity is calculated using a Bin-Beta model with prior (a,b). If the probability exceeds the threshold for a given dose, that dose and all doses above are excluded from further escalation. This is a hard safety rule that limits further escalation based on the observed data per dose level, independent from the underlying model.

Usage

IncrementsHSRBeta(target = 0.3, prob = 0.95, a = 1, b = 1)

.DefaultIncrementsHSRBeta()

Arguments

target

(proportion)
see slot definition.

prob

(proportion)
see slot definition.

a

(number)
see slot definition.

b

(number)
see slot definition.

Slots

target

(proportion)
the target toxicity, except 0 or 1.

prob

(proportion)
the threshold probability (except 0 or 1) for a dose being toxic.

a

(number)
shape parameter \(a > 0\) of probability distribution Beta (a,b).

b

(number)
shape parameter \(b > 0\) of probability distribution Beta (a,b).

Note

Typically, end users will not use the .DefaultIncrementsHSRBeta() function.

Examples

# Limit the escalation with a hard safety criteria to the doses that are below
# the first dose that is toxic with a probability of 0.95.
my_increments <- IncrementsHSRBeta(target = 0.3, prob = 0.95)