Power and Sample Size for Exact Unconditional Test for Equivalence in Risk Ratio

Source: R/getDesignProportions.R

Obtains the power given sample size or obtains the sample size given power for exact unconditional test of equivalence in risk ratio.

getDesignRiskRatioExactEquiv(
  beta = NA_real_,
  n = NA_real_,
  riskRatioLower = NA_real_,
  riskRatioUpper = NA_real_,
  pi1 = NA_real_,
  pi2 = NA_real_,
  allocationRatioPlanned = 1,
  alpha = 0.05
)

Arguments

beta

The type II error.

n

The total sample size.

riskRatioLower

The lower equivalence limit of risk ratio.

riskRatioUpper

The upper equivalence limit of risk ratio.

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.

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.

  • riskRatioLower: The lower equivalence limit of risk ratio.

  • riskRatioUpper: The upper equivalence limit of risk ratio.

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

  • pi2: The assumed probability for the control group.

  • riskRatio: The risk ratio.

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

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

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

Author

Kaifeng Lu, kaifenglu@gmail.com

Examples


getDesignRiskRatioExactEquiv(
  n = 200, riskRatioLower = 0.8, riskRatioUpper = 1.25,
  pi1 = 0.775, pi2 = 0.775, alpha = 0.05)
#>   alpha attainedAlphaH10 attainedAlphaH20     power   n riskRatioLower
#> 1  0.05       0.04691224       0.04691224 0.7514153 200            0.8
#>   riskRatioUpper   pi1   pi2 riskRatio allocationRatioPlanned
#> 1           1.25 0.775 0.775         1                      1
#>   zstatRiskRatioLower zstatRiskRatioUpper
#> 1            1.689398           -1.689398