samplesizeRiskDiffExactEquiv: Sample Size for Exact Unconditional Test of Equivalence in...

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

Sample Size for Exact Unconditional Test of Equivalence in Risk Difference

Description

Obtains the sample size given power for exact unconditional test of equivalence in risk difference.

Usage

samplesizeRiskDiffExactEquiv(
  beta = NA_real_,
  riskDiffLower = NA_real_,
  riskDiffUpper = NA_real_,
  pi1 = NA_real_,
  pi2 = NA_real_,
  allocationRatioPlanned = 1,
  alpha = 0.05,
  calculateAttainedAlpha = TRUE,
  max_n_search = 1000L,
  window = 10L
)

Arguments

beta	The type II error.
riskDiffLower	The lower equivalence limit of risk difference.
riskDiffUpper	The upper equivalence limit of risk difference.
pi1	The assumed probability for the active treatment group.
pi2	The assumed probability for the control group.
allocationRatioPlanned	Allocation ratio for the active treatment versus control. Defaults to 1 for equal randomization.
alpha	The significance level for each of the two one-sided tests. Defaults to 0.05.
calculateAttainedAlpha	Whether to calculate the attained alpha.
max_n_search	The maximum sample size to search up to. If no sample size up to this value satisfies the windowed power criterion, an error is thrown.
window	The number of consecutive sample sizes that must all satisfy the power criterion to confirm the found sample size. This is to mitigate non-monotonicity of power in sample size for the exact test.

Value

A data frame with the following variables:

• alpha: The specified significance level for each of the two one-sided tests.

• attainedAlpha: The attained significance level.

• power: The power.

• n: The sample size.

• riskDiffLower: The lower equivalence limit of risk difference.

• riskDiffUpper: The upper equivalence limit of risk difference.

• pi1: The assumed probability for the active treatment group.

• pi2: The assumed probability for the control group.

• riskDiff: The risk difference.

• allocationRatioPlanned: Allocation ratio for the active treatment versus control.

• zstatRiskDiffLower: The efficacy boundaries on the z-test statistic scale for the one-sided null hypothesis on the lower equivalence limit.

• zstatRiskDiffUpper: The efficacy boundaries on the z-test statistic scale for the one-sided null hypothesis on the upper equivalence limit.

Author(s)

Kaifeng Lu, [e-mail]

Examples

samplesizeRiskDiffExactEquiv(
  beta = 0.2, riskDiffLower = -0.3, riskDiffUpper = 0.3,
  pi1 = 0.9, pi2 = 0.9, alpha = 0.05)

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