twoCoprimary (version 1.0.0)

twoCoprimary2Continuous: Unified Interface for Two Co-Primary Continuous Endpoints

Description

This function provides a unified interface for both power calculation and sample size determination for two co-primary continuous endpoints. Depending on which parameters are provided (sample sizes or power), the function automatically determines whether to calculate power or sample size.

Usage

twoCoprimary2Continuous(
  n1 = NULL,
  n2 = NULL,
  delta1,
  delta2,
  sd1,
  sd2,
  rho,
  power = NULL,
  r = NULL,
  alpha = 0.025,
  known_var = TRUE,
  nMC = 10000
)

Value

An object of class "twoCoprimary" containing either:

• Power calculation results (when n1 and n2 are specified)

• Sample size calculation results (when power and r are specified)

Arguments

n1

Sample size for group 1 (treatment group). If NULL, will be calculated.

n2

Sample size for group 2 (control group). If NULL, will be calculated.

delta1

Mean difference for the first endpoint

delta2

Mean difference for the second endpoint

sd1

Common standard deviation for the first endpoint

sd2

Common standard deviation for the second endpoint

rho

Common correlation between the two outcomes

power

Target power (1 - beta). If NULL, will be calculated.

r

Allocation ratio (n1/n2). Required when calculating sample size.

alpha

One-sided significance level (typically 0.025 or 0.05)

known_var

Logical indicating whether variance is known (TRUE) or unknown (FALSE). Default is TRUE.

nMC

Number of Monte Carlo simulations when known_var = FALSE. Default is 10000.

Details

This function serves as a unified interface similar to power.prop.test(). The function determines the operation mode based on which parameters are NULL:

• If n1 and n2 are provided and power is NULL: calculates power

• If power and r are provided and n1/n2 are NULL: calculates sample size

Exactly one of {(n1, n2), (power, r)} must be NULL.

Examples

# Calculate power given sample sizes
twoCoprimary2Continuous(
  n1 = 100, n2 = 100,
  delta1 = 0.5, delta2 = 0.5,
  sd1 = 1, sd2 = 1,
  rho = 0.3, alpha = 0.025,
  known_var = TRUE
)

# Calculate sample size given target power
twoCoprimary2Continuous(
  delta1 = 0.5, delta2 = 0.5,
  sd1 = 1, sd2 = 1,
  rho = 0.3, power = 0.8,
  r = 1, alpha = 0.025,
  known_var = TRUE
)