Analysis of Panel Count Data with Time-dependent Covariates and Informative Observation Process

Panel count data occur in many clinical and observational studies and in some situations the observation process is informative.In this article,we propose a new joint model for the analysis of panel count data with time-dependent covariates and possibly in the presence of informative observation process via two latent variables.For the inference on the proposed model,a class of estimating equations is developed and the resulting estimators are shown to be consistent and asymptotically normal.In addition,a lack-of-fit test is provided for assessing the adequacy of the model.The finite-sample behavior of the proposed methods is examined through Monte Carlo simulation studies which suggest that the proposed approach works well for practical situations.Also an illustrative example is provided.