Kernel Smoothed Profile Likelihood Estimation in the Accelerated Failure Time Frailty Model for Clustered Survival Data.

This article considers an accelerated failure time frailty model for clustered survival data and develops nonparametric maximum likelihood estimation for it via a kernel smoother aided EM algorithm and shows that the proposed estimator for the regression coefficients is consistent, asymptotically normal and semiparametric efficient when the kernel bandwidth is properly chosen.