objectives : schizophrenia patients often experience relapses once and even more with no limit on number of relapses. the time among relapses are rarely considered in studies. the aim of this study was to identify some risk factors of time to elapses in schizophrenic patients with recurrent events model in survival analysis. methods : in a retrospective longitudinal study, the medical records o...

Background and objectives: Birth spacing is an important variable for identification of fertility acceleration, total fertility rate, and maternal and fetal health. Therefore, special attention has been paid to this issue by researchers in the fields of medical sciences, health, and population. In addition, proper analysis of this concept is of foremost importance. Application of classical anal...

Repeated events processes are ubiquitous across a great range of important health, medical, and public policy applications, but models for these processes have serious limitations. Alternative estimators often produce different inferences concerning treatment effects due to bias and inefficiency. We recommend a robust strategy for the estimation of effects in medical treatments, social conditio...

In clinical and observational studies, recurrent event data (e.g., hospitalization) with a terminal event (e.g., death) are often encountered. In many instances, the terminal event is strongly correlated with the recurrent event process. In this article, we propose a semiparametric method to jointly model the recurrent and terminal event processes. The dependence is modeled by a shared gamma fr...

background : time to donating blood plays a major role in a regular donor to becoming continues one. the aim of this study was to determine the effective factors on the interval between the blood donations. methods : in a longitudinal study in 2008, 864 samples of first-time donors in shahrekord blood transfusion center,  capital city of chaharmahal and bakhtiari province, iran were selected by...

The joineR package implements methods for analysing data from longitudinal studies in which the response from each subject consists of a time-sequence of repeated measurements and a possibly censored time-toevent outcome. The modelling framework for the repeated measurements is the linear model with random effects and/or correlated error structure. The model for the time-to-event outcome is a C...

Many analysis in epidemiological and prognostic studies and in studies of event history data require methods that allow for unobserved covariates or “frailties”. We consider the shared frailty model in the frame work of parametric proportional hazard model. There are certain assumptions about the distribution of frailty and baseline distribution. Mostly gamma distribution is considered for frai...

There has been an increasing interest in the analysis of recurrent event data (Cook and Lawless, 2002, Statistical Methods in Medical Research 11, 141-166). In many situations, a terminating event such as death can happen during the follow-up period to preclude further occurrence of the recurrent events. Furthermore, the death time may be dependent on the recurrent event history. In this articl...

Multiple sequential recurrences are one of themost important characteristics of superficial transitional cell carcinoma of the bladder, more than 50% of the patients will have recurrences (reappearance of a new superficial tumor). When in the same subject recurrent events are considered and these observed events are clustered into groups, independence between the clustered survival times cannot...