治療効果の大きさに関する頑健で解釈可能なハザードに基づく要約尺度とその推測方法

抄録

The hazard ratio based on Cox’s proportional hazards model is the most popular measure used to quantify the magnitude of the treatment effect on time-to-event outcomes in clinical research. However, the limitations of using the traditional Cox’s hazard ratio as a summary of the magnitude of the treatment effect on time-to-event outcomes have been widely discussed, and alternative measures that do not have such limitations (e.g., difference or ratio of restricted mean survival time) are gaining attention. One of the alternative methods recently proposed in a simple two-sample comparison setting uses the average hazard with survival weight (AH), which can be interpreted as the general censoring-free person-time incidence rate in a given time window. The difference in AH or ratio of AH does not have the limitations of Cox’s hazard ratio as a summary measure of the between-group difference. In this paper, we review the main limitations of Cox’s hazard ratio and the definition and interpretation of the AH proposed by Uno and Horiguchi (2023), along with the nonparametric inference procedure and a data example.