stopbound_pred {ph2bayes}

The stopping boundaries based on Lee and Liu's criterion

Description

The stopping boundaries based on Lee and Liu's criterion.

Usage

stopbound_pred(theta, type, nmax, alpha_e, beta_e, p_s, theta_t)

Arguments

theta

the cutoff probability: typically, \theta = [0.95, 0.99] for superiority, \theta = [0.01, 0.05] for futility.

type

type of boundaries: "superiority" or "futility".

nmax

the maximum number of patients treated by the experimental drug.

alpha_e

the hyperparameter (shape1) of the Beta prior for the experimental drug.

beta_e

the hyperparameter (shape2) of the Beta prior for the experimental drug.

p_s

the the response rate for the standard drug.

theta_t

the prespecified target probability; tipically, \theta_T = [0.85, 0.95].

Value

boundset

the boundaries set: U_n or L_n

References

Lee, J. J., Liu, D. D. (2008). A predictive probability design for phase II cancer clinical trials. Clinical Trials 5: 93-106.

Yin, G. (2012). Clinical Trial Design: Bayesian and Frequentist Adaptive Methods. New York: Wiley.

Examples

stopbound_pred(0.05, "futility", 40, 0.6, 1.4, 0.3, 0.85)
stopbound_pred(0.05, "futility", 30, 0.4, 1.6, 0.2, 0.85)
stopbound_pred(0.95, "superiority", 40, 0.6, 1.4, 0.3, 0.85)