论文标题
分层因子调整对事件时间分析的影响
Impact of the adjustment of stratification factors on time-to-event analyses
论文作者
论文摘要
在具有时间到事件终点的分层临床试验设计中，通常将分层因子用于对数秩检验和COX回归分析。在这项工作中，我们评估了包含分层因子对分层测试功率的影响，并比较了多变量和分层COX回归分析分析的偏差和标准误差。我们研究的结果表明，在存在预后效应的情况下未能考虑分层因子和少量事件的分层可能会大大降低对数秩检验的功能。此外，与分层的COX分析相比，多元COX分析的HR估计值更准确和精确。我们的发现表明，在研究设计时进行了分层因素对事件分析时间的影响，目前不是规范。
In a stratified clinical trial design with time to event end points, stratification factors are often accounted for the log-rank test and the Cox regression analyses. In this work, we have evaluated the impact of inclusion of stratification factors on the power of the stratified log-rank test and have compared the bias and standard error in HR estimate between multivariate and stratified Cox regression analyses through simulation. Results from our investigation suggests that both failing to consider stratification factor in presence of their prognostic effect and stratification with smaller number of events may substantially reduce the power of the log-rank test. Further, the HR estimate from the multivariate Cox analysis is more accurate and precise compared to the stratified Cox analysis. Our findings point towards the necessity of evaluating the impact of stratification factors on the time to event analyses at the time of study design which is presently not a norm.
