DelayedEffect.Design (version 1.1.3)

pow.SEPPLE.plus: SEPPLE+ power computation

Description

Perform the power calculation using the numeric SEPPLE+ method based on the generalized piecewise weighted log-rank test when the treatment time-lag effect is present and the lag duration varies heterogeneously from individual to individual or from study to study, within a certain domain and following a specific pattern.

Usage

pow.SEPPLE.plus(lambda1, tl, tu, N, HR, tao, A, dist="uniform",
              shape1=NULL, shape2=NULL, ap=0.5, alpha=0.05, nsim=10000)

Value

The power

Arguments

lambda1

Baseline hazard

tl

Lower bound of delayed duration domain

tu

Upper bound of delayed duration domain

N

Sample size

HR

Post-delay hazard ratio after tu, defined as the post-delay hazard rate of the treatment group compared to that of the control group

tao

Total study duration

A

Total enrollment duration

dist

One of "uniform", "beta" or "gamma", for the lag distribution

shape1

NULL or a positive parameter value for the beta or gamma distribution.

shape2

NULL or a positive parameter value for the beta or gamma distribution.

ap

Experimental-control allocation ratio. The default is 0.5.

alpha

Type I error rate (two-sided). The default is 0.05.

nsim

Number of simulations. The default is 10000.

Author

Zhenzhen Xu <[e-mail]> , Boguang Zhen<[e-mail]>, Yongsoek Park <[e-mail]> and Bin Zhu <[e-mail]>

Details

SEPPLE+ is an acronym for:
Simulation-based Empirical Power calculation method based on generalized Piecewise weighted Log-rank tEst with random treatment time-lag effect. See the reference for details of this method.

References

Xu, Z., Park, Y., Zhen, B. & Zhu, B. (2017). Achieving optimal power of logrank test with random treatment time-lag effect. Biometrika. Under review.

Xu, Z., Zhen, B., Park, Y., & Zhu, B. (2017). Designing therapeutic cancer vaccine trials with delayed treatment effect. Statistics in medicine, 36(4), 592-605.

See Also

pow.SEPPLE.random.DE, pow.sim.logrk.random.DE

Examples

  lambda1 <- 0.001982
  tl      <- 30
  tu      <- 30*11
  N       <- 200
  HR      <- 0.55
  tao     <- 365*3
  A       <- 365
  shape1  <- 5
  shape2  <- 5
  pow.SEPPLE.plus(lambda1, tl, tu, N, HR, tao, A, dist="beta", 
                  shape1=shape1, shape2=shape2, nsim=1000)