blindrecalc: Student – R documentation

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Student

Student's t test

Description

This class implements Student's t-test for superiority and non-inferiority tests. A trial with continuous outcomes of the two groups T and C is assumed. If alternative == "greater" the null hypothesis for the mean difference Δ = μ_T - μ_C is

H₀: Δ ≤ -δ_NI vs. H₁: Δ > -δ_NI.

_NI

alternative=="smaller"

The function setupStudent creates an object of class Student that can be used for sample size recalculation.

Usage

setupStudent(
  alpha,
  beta,
  r = 1,
  delta,
  delta_NI = 0,
  alternative = c("greater", "smaller"),
  n_max = Inf,
  ...
)

Arguments

`alpha`	One-sided type I error rate.
`beta`	Type II error rate.
`r`	Allocation ratio between experimental and control group.
`delta`	Difference of effect size between alternative and null hypothesis.
`delta_NI`	Non-inferiority margin.
`alternative`	Does the alternative hypothesis contain greater (`greater`) or smaller (`smaller`) values than the null hypothesis.
`n_max`	Maximal overall sample size. If the recalculated sample size is greater than `n_max` it is set to `n_max`.
`...`	Further optional arguments.

Details

The notation is based on the paper of Lu (2019): Distribution of the two-sample t-test statistic following blinded sample size re-estimation. Pharmaceutical Statistics 15: 208-215.

The following methods are available for this class: toer, pow, n_dist, adjusted_alpha, and n_fix. Check the design specific documentation for details.

Value

An object of class Student.

Examples

d <- setupStudent(alpha = .025, beta = .2, r = 1, delta = 3.5, delta_NI = 0,
                   alternative = "greater", n_max = 156)

blindrecalc

Blinded Sample Size Recalculation

v0.1.2

MIT + file LICENSE

Authors

Lukas Baumann [aut], Maximilian Pilz [aut, cre], Institute of Medical Biometry and Informatics - University of Heidelberg [cph]

Initial release