Multistate Models on Pleural Effusion after Allogeneic Hematopoietic Stem Cell Transplantation.

A multistate model is more complicated than competing risk models and composed of finite number of states and transitions between states. Unlike competing risk models, this model has the ability to assess the effect of occurrence order of time-to-event data. Pleural effusion (PE) is a severe complication that often occurs after allogeneic hematopoietic stem cell transplantation (HSCT). Many patients develop pleural effusion during the first 100 days after allogeneic HSCT and graft-versus-host disease (GVHD) occurs either before or after the development of PE, implying that the occurrence order of PE and GVHD (i.e., PE after GVHD vs. GVHD after PE) would influence on the incidence, risk factors and mortality of pleural effusion. One can use either Cox proportional models or competing risk models to evaluate these values, but neither method is able to incorporate the occurrence order of incidence into the model. To resolve this difficulty, we developed a multistate model describing several possible events and event-related dependences and applied to a retrospective study of 606 patients, including eight covariates.