N.APPLE.plus | R Documentation |
Perform the sample size calculation given the power and post-delay hazard ratio using the close-form APPLE+ 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.
N.APPLE.plus(lambda1, tl, tu, HR, tao, A, beta, ap=0.5, alpha=0.05)
lambda1 |
Baseline hazard |
tl |
Lower bound of delayed duration domain |
tu |
Upper bound of delayed duration domain |
HR |
Post-delay hazard ratio after |
tao |
Total study duration |
A |
Total enrollment duration |
beta |
Type II error rate; Power=1-beta |
ap |
Experimental-control allocation ratio. The default is 0.5. |
alpha |
Type I error rate (two-sided). The default is 0.05. |
APPLE+ is an acronym for:
Analytic 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.
The sample size
Zhenzhen Xu <Zhenzhen.Xu@fda.hhs.gov>, Boguang Zhen<Boguang.Zhen@fda.hhs.gov>, Yongsoek Park <yongpark@pitt.edu> and Bin Zhu <bin.zhu@nih.gov>
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.
pow.APPLE.plus
, HR.APPLE.plus
lambda1 <- 0.001982
tl <- 30
tu <- 30*11
HR <- 1.3
tao <- 365*3
A <- 365
beta <- 0.2
N.APPLE.plus(lambda1, tl, tu, HR, tao, A, beta)
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