Epgo_bias_normal: Expected probability to go to phase III for bias adjustment...

In Sterniii3/drugdevelopR: Utility-Based Optimal Phase II/III Drug Development Planning

Expected probability to go to phase III for bias adjustment programs with normally distributed outcomes

Description

In the case we do not only want do discount for overoptimistic results in phase II when calculating the sample size in phase III, but also when deciding whether to go to phase III or not the functions Epgo_normal_L2 and Epgo_normal_R2 are necessary. The function Epgo_normal_L2 uses an additive adjustment parameter (i.e. adjust the lower bound of the one-sided confidence interval), the function Epgo_normal_R2 uses a multiplicative adjustment parameter (i.e. use estimate with a retention factor)

Usage

Epgo_normal_L2(kappa, n2, Adj, w, Delta1, Delta2, in1, in2, a, b, fixed)

Epgo_normal_R2(kappa, n2, Adj, w, Delta1, Delta2, in1, in2, a, b, fixed)

Arguments

kappa	threshold value for the go/no-go decision rule
n2	total sample size for phase II; must be even number
Adj	adjustment parameter
w	weight for mixture prior distribution
Delta1	assumed true treatment effect for standardized difference in means
Delta2	assumed true treatment effect for standardized difference in means
in1	amount of information for Delta1 in terms of sample size
in2	amount of information for Delta2 in terms of sample size
a	lower boundary for the truncation
b	upper boundary for the truncation
fixed	choose if true treatment effects are fixed or random, if TRUE Delta1 is used as fixed effect

Value

The output of the functions Epgo_normal_L2 and Epgo_normal_R2 is the expected number of participants in phase III with conservative decision rule and sample size calculation.

Examples

res <- Epgo_normal_L2(kappa = 0.1, n2 = 50, Adj = 0, w = 0.3,
                               Delta1 = 0.375, Delta2 = 0.625, in1 = 300, in2 = 600, 
                               a = 0.25, b = 0.75, fixed = FALSE)
          res <- Epgo_normal_R2(kappa = 0.1, n2 = 50, Adj = 1, w = 0.3,
                               Delta1 = 0.375, Delta2 = 0.625, in1 = 300, in2 = 600, 
                               a = 0.25, b = 0.75, fixed = FALSE)

Sterniii3/drugdevelopR documentation built on Jan. 26, 2024, 6:17 a.m.