des_one_stage determines one-stage two-arm randomised clinical trial
designs, assuming the primary outcome variable is Bernoulli distributed. It
supports a flexible framework for specifying which scenarios to control the
type-I and type-II error-rates for, and allows for design determination
assuming a variety of test statistics. In all instances, des_one_stage
computes the optimal required sample size in each arm, the associated optimal
stopping boundaries, and returns information on key operating
characteristics.
des_one_stage(
type = "binomial",
alpha = 0.1,
beta = 0.2,
delta = 0.2,
ratio = 1,
Pi0 = 0.1,
Pi1 = Pi0[1],
nCmax = 50L,
summary = FALSE
)A character string indicating the chosen design
framework/test statistic to assume. Must be one of "barnard",
"binomial", "fisher", or "sat". Defaults to
"binomial".
A numeric indicating the chosen value for
, the significance level
(i.e., the type-I error-rate). Defaults to 0.1.
A numeric indicating the chosen value for
, used in the definition of
the desired power (i.e., the type-II error-rate). Defaults to 0.2.
A numeric indicating the chosen value for
, the treatment effect
assumed in the power calculation. Defaults to 0.2.
A numeric indicating the chosen value for
, the allocation ratio to
the experimental arm, relative to the control arm. Defaults to 1.
A numeric vector indicating the
chosen value for ,
the control arm response rates to control the type-I error-rate to level
for. Must either be of
length one, indicating a single point, or of
length two. In this case, the elements indicate the
range of possible response rates to allow for. Defaults to 0.1.
A numeric vector indicating the
chosen value for ,
the control arm response rates to allow for in the power calculations. Must
either be of length one, indicating a single point, or of
length two. In this case, the elements indicate the range of
possible response rates to allow for. Defaults to Pi0[1].
A numeric indicating the maximum value of the
sample size in the control arm to consider in the search procedure. Defaults
to 50L.
A logical variable indicating whether a summary
of the function's progress should be printed to the console. Defaults to
FALSE.
A list with additional class "ph2rand_des",
containing each of the input parameters along with several additional
variables, including
A list in the slot $boundaries giving the
rejection boundary/boundaries of the optimal design. The names of these
elements depends on the value of type.
A tibble in the slot $feasible summarising the
operating characteristics of the feasible designs.
A numeric in the slot $nC giving the sample size
in the control arm for the optimal design.
A numeric in the slot $nE giving the sample size
in the experimental arm for the optimal design.
A tibble in the slot $opchar summarising the
operating characteristics of the optimal design.
des_two_stage, opchar,
pmf, sim, terminal,
plot.ph2rand_des, summary.ph2rand_des.
# NOT RUN {
# The design for the default parameters
des <- des_one_stage()
# Controlling the type-I/II error-rates over a range of possible response
# rates
des_range <- des_one_stage(Pi0 = c(0, 1),
Pi1 = c(0, 0.8))
# }
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