术语“Arjas作图”的详细信息

英译术语:

Arjas plot

汉语语境:

Arjas作图可以检验一个绝对协变量是否应包括在一个比例风险模型以及此协变量是否具有比例风险。每级绘制一条线。如果协变量并不需要出现在模型中，那么就要为每个值通过原点作大致45°线。否则Arjas作图将作出近似线性曲线，而斜率不是1.如果一个协变量对风险率有非比例作用，曲线将不同于非线性45°线。假定指示变量只有两个值，0和1，当取值为1时，该曲线为凹，如果风险比率增加，取值为0，曲线是凸的。

英语语境:

Arjas plots allow to check if a categorical covariate should be included in a proportional hazards model and if this covariate has proportional hazards. For each level a line is plotted. If the covariate does not need to be in the model then for each value a roughly 45° line through origin should be plotted. Otherwise Arjas plots will give curves which are approximately linear but with slope differing from 1. If a covariate has a nonproportional effect on the hazard rate then the curves will differ nonlinearly from 45° line. Assume an indicator variable having only two values 0 and 1, the curve for the level 1 should be concave if the hazard ratio is increasing in t whereas the curve for the level 0 should be convex.