calc.bnd.surv: Stopping Boundary Calculation (Survival Data)

In stoppingrule: Create and Evaluate Stopping Rules for Safety Monitoring

Stopping Boundary Calculation (Survival Data)

Description

Internal workhorse function to calculate stopping boundary for a given method for time-to-event data

Usage

calc.bnd.surv(n, p0, type, tau, cval, maxInf = "expected", param = NULL)

Arguments

n	maximum sample size for safety monitoring
p0	The probability of a toxicity occurring in tau units of time under the null hypothesis
type	The method used for constructing the stopping rule
tau	Length of observation period
cval	Critical value for the stopping rule. For Wang-Tsiatis tests, this is the Delta parameter. For the Bayesian Gamma-Poisson method, this is the threshold on the posterior probability. For the truncated SPRT, this is the threshold on the log likelihood ratio. For the MaxSPRT, this is the threshold on the log generalized likelihood ratio.
maxInf	Specification of the maximum information (maximum exposure time) used for designing the stopping rule. Options include the expected exposure time for n patients used H0 ("expected") and the maximum possible exposure time ("maximum"). Default is "expected" (expected exposure time in cohort).
param	A vector of the extra parameter(s) needed for certain stopping rule methods. For Wang-Tsiatis tests, this is the Delta parameter. For truncated SPRT, this is the targeted alternative toxicity probability p1. For Bayesian Gamma-Poisson model, this is the vector of hyperparameters (shape,rate) for the gamma prior on the toxicity event rate.

Value

A list of three items: tau, number of events that can trigger a stop, and the corresponding total follow up time.

stoppingrule documentation built on April 12, 2025, 1:55 a.m.