getADCI_mams: Confidence Interval After Adaptation for Multi-Arm...

In lrstat: Power and Sample Size Calculation for Non-Proportional Hazards and Beyond

Confidence Interval After Adaptation for Multi-Arm Multi-Stage Design

Description

Obtains the p-value, conservative point estimate, and confidence interval after the end of an adaptive multi-arm multi-stage trial.

Usage

getADCI_mams(
  M = NA_integer_,
  r = 1,
  corr_known = TRUE,
  L = NA_integer_,
  zL = NA_real_,
  IMax = NA_real_,
  kMax = NA_integer_,
  informationRates = NA_real_,
  efficacyStopping = NA_integer_,
  criticalValues = NULL,
  alpha = 0.25,
  typeAlphaSpending = "sfOF",
  parameterAlphaSpending = NA_real_,
  spendingTime = NA_real_,
  MullerSchafer = FALSE,
  MNew = NA_integer_,
  selected = NA_integer_,
  rNew = 1,
  Lc = NA_integer_,
  zLc = NA_real_,
  INew = NA_real_,
  informationRatesNew = NA_real_,
  efficacyStoppingNew = NA_integer_,
  typeAlphaSpendingNew = "sfOF",
  parameterAlphaSpendingNew = NA_real_,
  spendingTimeNew = NA_real_
)

Arguments

M	Number of active treatment arms in the primary trial.
r	Randomization ratio of each active arm to the common control in the primary trial.
corr_known	Logical. If TRUE, the correlation between Wald statistics is derived from the randomization ratio r as r / (r + 1). If FALSE, a conservative correlation of 0 is assumed.
L	The interim adaptation look of the primary trial.
zL	The z-test statistics at the interim adaptation look of the primary trial.
IMax	Maximum information for any active arm versus the common control for the primary trial. Must be provided.
kMax	The maximum number of stages of the primary trial.
informationRates	The information rates of the primary trial.
efficacyStopping	Indicators of whether efficacy stopping is allowed at each stage of the primary trial. Defaults to TRUE if left unspecified.
criticalValues	The matrix of by-level upper boundaries on the max z-test statistic scale for efficacy stopping up to look L for the primary trial. The first column is for level M, the second column is for level M - 1, and so on, with the last column for level 1. If left unspecified, the critical values will be computed based on the specified alpha spending function.
alpha	The significance level of the primary trial. Defaults to 0.025.
typeAlphaSpending	The type of alpha spending for the primary trial. One of the following: "OF" for O'Brien-Fleming boundaries, "P" for Pocock boundaries, "WT" for Wang & Tsiatis boundaries, "sfOF" for O'Brien-Fleming type spending function, "sfP" for Pocock type spending function, "sfKD" for Kim & DeMets spending function, "sfHSD" for Hwang, Shi & DeCani spending function, and "none" for no early efficacy stopping. Defaults to "sfOF".
parameterAlphaSpending	The parameter value of alpha spending for the primary trial. Corresponds to \Delta for "WT", \rho for "sfKD", and \gamma for "sfHSD".
spendingTime	The error spending time of the primary trial. Defaults to missing, in which case, it is the same as informationRates.
MullerSchafer	Whether to use the Muller and Schafer (2001) method for trial adaptation.
MNew	The number of active treatment arms in the secondary trial.
selected	The indices of the selected treatment arms for the secondary trial among the M active arms in the primary trial.
rNew	The randomization ratio of each active arm to the common control in the secondary trial.
Lc	The termination look of the integrated trial.
zLc	The z-test statistics at the termination look of the integrated trial.
INew	The maximum information for any active arm versus the common control in the secondary trial.
informationRatesNew	The spacing of looks of the secondary trial.
efficacyStoppingNew	The indicators of whether efficacy stopping is allowed at each look of the secondary trial. Defaults to TRUE if left unspecified.
typeAlphaSpendingNew	The type of alpha spending for the secondary trial. One of the following: "OF" for O'Brien-Fleming boundaries, "sfOF" for O'Brien-Fleming type spending function, "sfP" for Pocock type spending function, "sfKD" for Kim & DeMets spending function, "sfHSD" for Hwang, Shi & DeCani spending function, and "none" for no early efficacy stopping. Defaults to "sfOF".
parameterAlphaSpendingNew	The parameter value of alpha spending for the secondary trial. Corresponds to \rho for "sfKD", and \gamma for "sfHSD".
spendingTimeNew	The error spending time of the secondary trial. Defaults to missing, in which case, it is the same as informationRatesNew.

Details

If typeAlphaSpendingNew is "OF" or "none", then informationRatesNew, efficacyStoppingNew, and spendingTimeNew must be of full length kNew, and informationRatesNew and spendingTimeNew must end with 1.

Value

A data frame with the following variables:

• level: Number of individual hypotheses considered for multiplicity.

• index: The treatment arm with max Z among the active arms.

• pvalue: p-value for rejecting the null hypothesis.

• thetahat: Point estimate of the parameter.

• cilevel: Confidence interval level.

• lower: Lower bound of confidence interval.

• upper: Upper bound of confidence interval.

Author(s)

Kaifeng Lu, [e-mail]

References

Ping Gao, Yingqiu Li. Adaptive multiple comparison sequential design (AMCSD) for clinical trials. Journal of Biopharmaceutical Statistics, 2024, 34(3), 424-440.

Examples

getADCI_mams(
  M = 2, r = 1, corr_known = FALSE, L = 1, zL = c(2.075, 2.264),
  IMax = 300 / 4, kMax = 2, informationRates = c(0.5, 1),
  alpha = 0.025, typeAlphaSpending = "sfOF",
  MNew = 1, selected = 2, rNew = 1,
  Lc = 2, zLc = 1.667, INew = 374 / 4)

lrstat documentation built on May 13, 2026, 9:06 a.m.