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

Source: `R/build_dtl_bern.R`
`build_dtl_bern.Rd`

`build_dtl_bern()` builds a multi-stage drop-the-losers multi-arm clinical trial design object assuming the primary outcome variable is Bernoulli distributed, like those returned by `des_dtl_bern`.

    build_dtl_bern(
      n1 = 210,
      n10 = 70,
      e = 2.17,
      Kv = c(2, 1),
      alpha = 0.025,
      beta = 0.1,
      pi0 = 0.3,
      delta1 = 0.2,
      delta0 = 0,
      ratio = 1,
      power = "marginal",
      type = "variable",
      summary = FALSE
    )

## Arguments

n1 | A `numeric` indicating the chosen value for n1, the total sample size required in stage one of the trial. Defaults to `147`.
n10 | A `numeric` indicating the chosen value for n10, the sample size required in the control arm in stage one of the trial. Defaults to `49`.
e | A `numeric` indicating the chosen value for e, the critical rejection boundary for the final analysis. Defaults to `2.17`.
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 `0.5`.
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"`.
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 `$maxN` specifying N, the trial's total required sample size.

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

- Each of the input variables.

## See also

`des_dtl_bern`, `gui`, `opchar_dtl_bern`, `plot.multiarm_des_dtl_bern`, `sim_dtl_bern`.

## Examples

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