Simulation studies showed a clear advantage of our new method over the proportional hazard based calculation across different non‐proportional hazard scenarios. Moreover, the mixture modeling of two real trials demonstrates how to use the prior information on the survival distribution among p...
Hazard ratioThis paper discusses two-sample comparison in the case of interval-censored failure time data. For the problem, one common approach is to employ some nonparametric test procedures, which usually give some p-values but not a direct or exact quantitative measure of the survival or ...
We provide a sample size calculation method for a composite endpoint (CE) based on the geometric average hazard ratio (gAHR) in case the proportional hazards assumption can be assumed to hold for the components, but not for the CE. Methods: The required number of events, sample size and ...
We provide a sample size calculation method for a composite endpoint (CE) based on the geometric average hazard ratio (gAHR) in case the proportional hazards assumption can be assumed to hold for the components, but not for the CE. Methods: The required number of events, sample size and ...
The simulated small-sample behaviours of several estimators of a common hazard ratio are compared. In most circumstances, a modified version of the empirical logit (Haldane 1955; Anscombe 1956) seems to be the analytic technique of choice. The performance of the Standardized Mortality Ratio (SMR)...
Effect sizes for the power calculation were based on prior work. In a study of 450 men who have sex with men aged 16–20 years old, Garofalo et al. reported the 12-month HIV incidence rate to be between 2.0 and 6.0, with 95% confidence [51]. To be conservative, we assumed a 30%...
Effect sizes for the power calculation were based on prior work. In a study of 450 men who have sex with men aged 16–20 years old, Garofalo et al. reported the 12-month HIV incidence rate to be between 2.0 and 6.0, with 95% confidence [51]. To be conservative, we assumed a 30%...
SAMPLE SIZE CALCULATION FOR COMPARING (为比较样本大小的计算).pdf,SAMPLE SIZE CALCULATION FOR proportional hazard model, and the log-rank COMPARING TIME-TO-EVENT DATA test, are discussed. The remaining of this article is orga- HANSHENG WANG nized as fol
aWe estimated that a sample of 900 patients would provide 90% power to detect a 20% reduction in the hazard ratio for death in the 33°C group as compared with the 36°C group, at a two-sided alpha level of 0.05. 我们估计与36° C组比较, 900名患者抽样在33° C组将提供90%力量查出...
Firstly, sample size and power calculations should always be carried out before the investigation commences, with reports stating how and why they chose that number of subjects to study. Secondly, there is little value in a post hoc calculation which takes the form of, for example, 'we ...