findDesigns: findDesigns

In martinlaw/SCsinglearm: Finds Stochastically Curtailed Design Realisations for Single-arm Binary Outcome Trials

Description

This function finds admissible design realisations for single-arm binary outcome trials, using stochastic curtailment. The output can be used as the sole argument in the function 'drawDiagram', which will return the stopping boundaries for the admissible design of your choice. Monitoring frequency can set in terms of block(/cohort) size ("C") or number of stages ("stages").

Usage

findDesigns(
  nmin,
  nmax,
  C = NA,
  stages = NA,
  p0,
  p1,
  alpha,
  power,
  maxthetaF = p1,
  minthetaE = p1,
  bounds = "wald",
  return.only.admissible = TRUE,
  max.combns = 1e+06,
  maxthetas = NA,
  fixed.r = NA,
  exact.thetaF = NA,
  exact.thetaE = NA
)

Arguments

nmin	Minimum permitted sample size. Should be a multiple of block size or number of stages.
nmax	Maximum permitted sample size. Should be a multiple of block size or number of stages.
C	Block size. Vectors, i.e., multiple values, are permitted.
stages	Number of interim analyses or "stages". Only required if not setting block size C. Vectors, i.e., multiple values, are permitted.
p0	Probability for which to control the type-I error-rate
p1	Probability for which to control the power
alpha	Significance level
power	Required power (1-beta).
maxthetaF	Maximum value of lower CP threshold theta_F_max. Defaults to p1.
minthetaE	Minimum value of upper threshold theta_E_min. Defaults to p1.
bounds	choose what final rejection boundaries should be searched over: Those of A'Hern ("ahern"), Wald ("wald") or no constraints (NA). Defaults to "wald".
return.only.admissible	Logical. Returns only admissible design realisations if TRUE, otherwise returns all feasible designs. Defaults to TRUE.
max.combns	Provide a maximum number of ordered pairs (theta_F, theta_E). Defaults to 1e6.
maxthetas	Provide a maximum number of CP values used to create ordered pairs (theta_F, theta_E). Can be used instead of max.combns. Defaults to NA.
fixed.r	Choose what final rejection boundaries should be searched over. Useful for reproducing a particular design realisation. Defaults to NA.
exact.thetaF	Provide an exact value for lower threshold theta_F. Useful for reproducing a particular design realisation. Defaults to NA.
exact.thetaE	Provide an exact value for upper threshold theta_E. Useful for reproducing a particular design realisation. Defaults to NA.

Value

Output is a list of two dataframes. The first, $input, is a one-row data frame that contains all the arguments used in the call. The second, $all.des, contains the operating characteristics of all admissible designs found.

Author(s)

Martin Law, [e-mail]

Examples

findDesigns(nmin = 20, nmax = 20, C = 1, p0 = 0.1, p1 = 0.4, power = 0.8, alpha = 0.1)

martinlaw/SCsinglearm documentation built on Feb. 19, 2021, 8:05 p.m.