DBCD_BINARY {RARfreq}

Doubly Adaptive Biased Coin Design (Binary Responses)

Description

Allocates patients to one of treatments based on doubly adaptive biased coin design on summary level data.

Usage

DBCD_BINARY(S_RK, N_RK, group_allo, rho_func_index, rho_func, alpha)

Arguments

S_RK

A vector of current success rates for each treatment arm.

N_RK

A vector of current enrolled subjects in each arm. The length must be the same as 'S_RK'.

group_allo

An integer of the size of group allocation. The default is 1.

rho_func_index

Supply a number of 1, 2 or 3 indicting the allocation function to use. 1 = Wei's allocation; 2 = Neyman allocation; 3 = Rosenberger allocation. The default is 3.

rho_func

Supply a user-specified allocation function of S_RK when rho_func_index is NULL. Default is NULL.

alpha

Supply a number indicating the subscripts of the probability function. The default is 2.

Details

'DBCD_BINARY' assigns the next subject to a group given the observed success rates, enrolled subjects and allocation function.

Value

Number of the arm that the next subject is assigned to.

Examples

# There are 3 arms each of which receives 25 patients.
# The observed response rates are 40%, 28% and 60%, respectively.
# The following command returns the number of arm that the next patient will
# be assigned to.
DBCD_BINARY(S_RK = c(0.4, 0.28, 0.6),
            N_RK = c(25, 25, 25),
            rho_func_index = 3, alpha=2)

# Urn allocation
DBCD_BINARY(S_RK = c(0.4, 0.3),
            N_RK = c(25, 25),
            group_allo = 1,
            rho_func_index = NULL,
            rho_func = function(x) rev(1-x)/sum(1-x),
            alpha=2)