ASSESSING GOODNESS-OF-FIT OF PARAMETRIC REGRESSION-MODELS FOR LIFETIME DATA - GRAPHICAL METHODS

Graphical methods are often used to check goodness-of-fit of models to data. It is common to plot residuals against a reference distribution so that when the model fits the data, the configuration should be clo se to a straight line. Since the resemblance to a straight line is oft en unclear, it has been suggested to add simulated envelopes within wh ich the configuration is expected to lie. The implementation of this m ethod for survival data analysis is not straightforward. In this paper we point out the difficulties which arise in constructing envelopes o n residual plots for randomly censored data. Methods are suggested to deal with the problems and evaluated; they are illustrated by simulate d data and on a follow-up study of myeloma.