Design a multi-stage drop-the-losers multi-arm clinical trial for a Bernoulli distributed primary outcome

des_dtl_bern() determines multi-stage drop-the-losers multi-arm clinical trial designs assuming the primary outcome variable is Bernoulli distributed. It computes required design components and returns information on key operating characteristics.

des_dtl_bern(
  Kv = c(2, 1),
  alpha = 0.025,
  beta = 0.1,
  pi0 = 0.3,
  delta1 = 0.2,
  delta0 = 0,
  ratio = 1,
  power = "marginal",
  type = "variable",
  integer = F,
  summary = F
)

Arguments

Kv	A numeric vector of strictly decreasing values, indicating the chosen value for K, the number of experimental treatment arms present in each stage. Defaults to c(2, 1).
alpha	A numeric indicating the chosen value for α, the significance level (family-wise error-rate). Defaults to 0.025.
beta	A numeric indicating the chosen value for β, used in the definition of the desired power. Defaults to 0.1.
pi0	A numeric indicating the chosen value for π0, the response rate in the control arm. Defaults to 0.3.
delta1	A numeric indicating the chosen value for δ1, the 'interesting' treatment effect. Defaults to 0.2.
delta0	A numeric indicating the chosen value for δ0, the 'uninteresting' treatment effect. Defaults to 0.
ratio	A numeric indicating the chosen value for r, the stage-wise allocation ratio to present experimental arms. Defaults to 1.
power	A character string indicating the chosen type of power to design the trial for. Can be "disjunctive" or "marginal". Defaults to "marginal".
type	A character string indicating the choice for the stage-wise sample size. Can be "variable" or "fixed". Defaults to "variable".
integer	A logical variable indicating whether the computed possible sample sizes required in each arm in each stage should be forced to be whole numbers. Defaults to FALSE. WARNING: If you set integer = TRUE and ratio != 1, obscure results can occur due to difficulties in identifying a suitable whole number sample size that meets the allocation ratio requirement.
summary	A logical variable indicating whether a summary of the function's progress should be printed to the console. Defaults to FALSE.

Value

A list, with additional class "multiarm_des_dtl_bern", containing the following elements:

• A tibble in the slot $opchar summarising the operating characteristics of the identified design.

• A numeric in the slot $e specifying e, the trial's critical rejection boundary for the final analysis.

• A numeric in the slot $maxN specifying N, the trial's total required sample size.

• A numeric in the slot $n_factor, for internal use in other functions.

• A numeric in the slot $n1 specifying n₁, the total sample size required in stage one of the trial.

• A numeric in the slot $n10 specifying n₁₀, the sample size required in the control arm in stage one of the trial.

• Each of the input variables.

See also

build_dtl_bern, gui, opchar_dtl_bern, plot.multiarm_des_dtl_bern, sim_dtl_bern.

Examples

# The design for the default parameters
des <- des_dtl_bern()