A Bartlett Type Correction for Rao's Score Test in Cox Regression Model

摘要

Gu and Zheng (1993) established a Bartlett adjustment for the partial likelihood ratio test in the Cox proportional hazards regression model. It is known that the same method of adjustment cannot be used to improve the accuracy of the test statistic derived by Rao's score method. In this paper, the method of Cordeiro and Ferrari (1991) is used to derive a Bartlett type correction for the score test in the Cox proportional hazards regression model. As a special case, a test which is more accurate than the popular log-rank test is obtained.