des_dtl_pois()
determines multi-stage drop-the-losers multi-arm
clinical trial designs assuming the primary outcome variable is Poisson
distributed. It computes required design components and returns information
on key operating characteristics.
des_dtl_pois(
Kv = c(2, 1),
alpha = 0.025,
beta = 0.1,
lambda0 = 5,
delta1 = 1,
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 . |
lambda0 |
A numeric indicating the chosen value for
λ0, the
event rate in the control arm. Defaults to 5 . |
delta1 |
A numeric indicating the chosen value for
δ1, the
'interesting' treatment effect. Defaults to 1 . |
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_pois"
, 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
Examples
# The design for the default parameters
des <- des_dtl_pois()