© 1997 by Biometrika Trust
On fitting Cox's regression model with time-dependent coefficients
Mathematical Institute, University of Wroclaw 50-384 Wroclaw, Poland e-mail: lmarzec{at}hera.math.uni.wroc.pl pmarzec{at}hera.math.uni.wroc.pl
This paper examines goodness-of-fit testing in the Cox regression model with time-varying regression coefficients. Arjas' (1988) approach is used to define test statistics of the Kolmogorov-Smirnov and Cramér-von Mises types. Their asymptotic limits are shown to be well-known functionals of standard Brownian motion, leading to the construction of formal goodness-of-fit tests. Some numerical studies are also included to illustrate the performance of the tests for moderate sample sizes.
Key Words: Counting process Cox regression model Goodness of fit Survival analysis Time-dependent coefficients Weak convergence