getSizeTTE {GenTwoArmsTrialSize}

General Formulas for Sample Size Calculation

Description

This function computes the sample size required for two arms clinical trials with TTE outcome measure. Four hypothesis tests are available under two allocation designs.

Usage

getSizeTTE(
  design = c("parallel", "crossover"),
  test = c("equality", "noninferiority", "superiority", "equivalence"),
  alpha = 0.05,
  beta = 0.2,
  varlambda,
  k = 1,
  ttotal,
  taccrual,
  gamma,
  delta = 0,
  rho = c(0.05, 0.07),
  r = 0.1
)

Arguments

design

allocation method (parallel or crossover).

test

four hypothesis tests: equality, noninferiority, superiority, and equivalence.

alpha

level of significance.

beta

type II error.

varlambda

(varlambda1>0,varlambda2>0):=(lam1,lam2) hazard rates in control and treatment arms

k

ratio of control to treatment.

ttotal

total trial time (ttoal>0)

taccrual

accrual time period (taccrual>0)

gamma

parameter of exponential distribution (gamma>=0)

delta

delta margin in test hypothesis.

rho

vector of length 2, positive noncompliance rates of two arms.

r

projected proportion of trial uniform loss of follow-up.

Value

sample size per arm.

Examples

# Ex 1. (n_trt=56, n_ctl=56)
getSizeTTE(design="parallel", test="equality", alpha=0.05, beta=0.20,
 varlambda=c(1,2), k=1, ttotal=3, taccrual=1, gamma=0.00001, delta=0,
 rho=c(0.05, 0.07), r=0.1)

# Ex 2. (n_trt=30, n_ctl=30)
getSizeTTE(design="parallel", test="noninferiority", alpha=0.05, beta=0.20,
 varlambda=c(1,2), k=1, ttotal=3, taccrual=1, gamma=0.00001, delta= -0.2,
 rho=c(0.05, 0.07), r=0.1)

# Ex 3. (n_trt=74, n_ctl=74)
getSizeTTE(design="parallel", test="superiority", alpha=0.05, beta=0.20,
varlambda=c(1,2), k=1, ttotal=3, taccrual=1, gamma=0.00001, delta=0.20,
rho=c(0.05, 0.07), r=0.1)

# Ex 4. (n_trt=84, n_ctl=84)
getSizeTTE(design="parallel", test="equivalence", alpha=0.05, beta=0.20,
 varlambda=c(1,1), k=1, ttotal=3, taccrual=1, gamma=0.00001, delta=0.5,
 rho=c(0.05, 0.07), r=0.1)

# Ex 5. (Check back next version)
getSizeTTE(design="crossover", test="equality", alpha=0.05, beta=0.20,
 varlambda=c(1,1), k=1, ttotal=3, taccrual=1, gamma=0.00001, delta=0.5,
 rho=c(0.05, 0.07), r=0.1)

# Ex 6. (Check back next version)
getSizeTTE(design="crossover", test="noninferiority", alpha=0.05,
 beta=0.20, varlambda=c(1,1), k=1, ttotal=3, taccrual=1, gamma=0.00001,
 delta=0.5, rho=c(0.05, 0.07), r=0.1)

# Ex 7. (Check back next version)
getSizeTTE(design="crossover", test="superiority", alpha=0.05, beta=0.20,
 varlambda=c(1,1), k=1, ttotal=3, taccrual=1, gamma=0.00001, delta=0.5,
 rho=c(0.05, 0.07), r=0.1)

# Ex 8. (Check back next version)
getSizeTTE(design="crossover", test="equivalence", alpha=0.05, beta=0.20,
 varlambda=c(1,1), k=1, ttotal=3, taccrual=1, gamma=0.00001, delta=0.5,
 rho=c(0.05, 0.07), r=0.1)