Joint analysis of panel count data with an informative observation process and a dependent terminal event.

Panel count data occur in many clinical and observational studies, and in many situations, the observation process may be informative and also there may exist a terminal event such as death which stops the follow-up. In this article, we propose a new joint model for the analysis of panel count data in the presence of both an informative observation process and a dependent terminal event via two latent variables. For the inference on the proposed models, 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 models. Simulation studies suggest that the proposed approach works well for practical situations. A real example from a bladder cancer clinical trial is used to illustrate the proposed methods.