Browsing by Subject "sample size"

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    Sample size determination for jointly testing a cause-specific hazard and the all-cause hazard in the presence of competing risks.
    (Stat Med, 2017-12-27) Yang, Qing; Fung, Wing K; Li, Gang
    This article considers sample size determination for jointly testing a cause-specific hazard and the all-cause hazard for competing risks data. The cause-specific hazard and the all-cause hazard jointly characterize important study end points such as the disease-specific survival and overall survival, which are commonly used as coprimary end points in clinical trials. Specifically, we derive sample size calculation methods for 2-group comparisons based on an asymptotic chi-square joint test and a maximum joint test of the aforementioned quantities, taking into account censoring due to lost to follow-up as well as staggered entry and administrative censoring. We illustrate the application of the proposed methods using the Die Deutsche Diabetes Dialyse Studies clinical trial. An R package "powerCompRisk" has been developed and made available at the CRAN R library.
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    The impact of lowering the study design significance threshold to 0.005 on sample size in randomized cancer clinical trials.
    (Journal of clinical and translational science, 2024-01) Leung, Tiffany H; Ho, James C; Wang, Xiaofei; Lam, Wendy W; Pang, Herbert H
    The proposal of improving reproducibility by lowering the significance threshold to 0.005 has been discussed, but the impact on conducting clinical trials has yet to be examined from a study design perspective. The impact on sample size and study duration was investigated using design setups from 125 phase II studies published between 2015 and 2022. The impact was assessed using percent increase in sample size and additional years of accrual with the medians being 110.97% higher and 2.65 years longer respectively. The results indicated that this proposal causes additional financial burdens that reduce the efficiency of conducting clinical trials.