The Explained Variation in Proportional Hazards Regression
提出了两个新指标，用于衡量比例风险模型对可能删失的生存时间变异的解释比例，并指出之前常用的对数似然解释比例不适合衡量预测精度。
Two new measures of the proportion of the variation of possibly censored survival times explained by a given proportional hazards model are presented. It is shown that the previously suggested proportion of explained log likelihood is not a useful measure of predictive precision. The new measures are intuitively appealing and sufficiently simple for routine application.