title: Modelling time-dependent interaction in a time-varying covariate and its application to rejection episodes and kidney transplant failure.
abstract: Acute rejection episodes are thought to be prognostic of eventual kidney graft failure. The influence of rejection events on the hazard of transplant failure appears to be a complex function of how long after transplantation the rejection event occurs as well as the time elapsed since the rejection event. To examine the nature of this relationship, we propose a penalized likelihood approach to estimate the parameters of a two-dimensional rectanglewise constant hazard model. The approach appears to be fairly successful at modelling time dependency in a time-varying covariate. The approach is equally applicable for modelling fixed covariates that act in a jointly nonproportional (non-log-linear) and time-dependent manner.
authors.affiliation: Department of Surgery, University of Wisconsin, Madison 53792, USA. heisey@surgery.wisc.edu
authors.forename: D M
authors.initials: DM
authors.lastname: Heisey
authors.forename: A P
authors.initials: AP
authors.lastname: Foong
mesh_terms: D000704:Analysis of Variance; D016572:Cyclosporine / Q000627:therapeutic use; D006084:Graft Rejection / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000276:immunology*; D016013:Likelihood Functions; D015233:Models, Statistical; D016853:Muromonab-CD3 / Q000627:therapeutic use; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013997:Time Factors; D017211:Treatment Failure
chemical_list: D007166:Immunosuppressive Agents; D016853:Muromonab-CD3; D016572:Cyclosporine