title: Joint frailty models for zero-inflated recurrent events in the presence of a terminal event.
abstract: Recurrent event data arise frequently in longitudinal medical studies. In many situations, there are a large portion of subjects without any recurrent events, manifesting the "zero-inflated" nature of the data. Some of the zero events may be "structural zeros" as patients are unsusceptible to recurrent events, while others are "random zeros" due to censoring before any recurrent events. On the other hand, there often exists a terminal event which may be correlated with the recurrent events. In this article, we propose two joint frailty models for zero-inflated recurrent events in the presence of a terminal event, combining a logistic model for "structural zero" status (Yes/No) and a joint frailty proportional hazards model for recurrent and terminal event times. The models can be fitted conveniently in SAS Proc NLMIXED. We apply the methods to model recurrent opportunistic diseases in the presence of death in an AIDS study, and tumor recurrences and a terminal event in a sarcoma study.
authors: Department of Preventive Medicine and Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois 60611, U.S.A.
authors: Lei
authors: L
authors: Liu
authors: Department of Biostatistics, M. D. Anderson Cancer Center, University of Texas, Houston, Texas 77030, U.S.A.
authors: Xuelin
authors: X
authors: Huang
authors: Vital Systems Inc., Rolling Meadows, Illinois 60008, U.S.A.
authors: Alex
authors: A
authors: Yaroshinsky
authors: Department of Surgical Oncology, M. D. Anderson Cancer Center, University of Texas, Houston, Texas 77030, U.S.A.
authors: Janice N
authors: JN
authors: Cormier
mesh_terms: D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D006801:Humans; D008137:Longitudinal Studies; D015233:Models, Statistical; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012509:Sarcoma / Q000401:mortality*; D012680:Sensitivity and Specificity; D016019:Survival Analysis
keywords: Cure model; Finite Mixture; Latent Class; Survival analysis