A modified partial likelihood score method for Cox regression with covariate error under the internal validation design.

We develop a new method for covariate error correction in the Cox survival regression model, given a modest sample of internal validation data. Unlike most previous methods for this setting, our method can handle covariate error of arbitrary form. Asymptotic properties of the estimator are derived. In a simulation study, the method was found to perform very well in terms of bias reduction and confidence interval coverage. The method is applied to data from the Health Professionals Follow‐Up Study (HPFS) on the effect of diet on incidence of Type II diabetes. [ABSTRACT FROM AUTHOR]