Recurrent event data arise in many biomedical longitudinal studies when health-related events can occur repeatedly for each subject during the follow-up time. In this article, we examine the gap times between recurrent events. We propose a new semiparametric accelerated gap time model based on the trend-renewal process which contains trend and renewal components that allow for the intensity function to vary between successive events. We use the Buckley-James imputation approach to deal with censored transformed gap times. The proposed estimators are shown to be consistent and asymptotically normal. Model diagnostic plots of residuals and a method for predicting number of recurrent events given specified covariates and follow-up time are also presented. Simulation studies are conducted to assess finite sample performance of the proposed method. The proposed technique is demonstrated through an application to two real data sets.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s10985-021-09519-3 | DOI Listing |
Stat Methods Med Res
December 2024
Department of Public Health Sciences, Queen's University, Kingston, ON, Canada.
The semiparametric accelerated failure time mixture cure model is an appealing alternative to the proportional hazards mixture cure model in analyzing failure time data with long-term survivors. However, this model was only proposed for independent survival data and it has not been extended to clustered or correlated survival data, partly due to the complexity of the estimation method for the model. In this paper, we consider a marginal semiparametric accelerated failure time mixture cure model for clustered right-censored failure time data with a potential cure fraction.
View Article and Find Full Text PDFStat Med
December 2024
Department of Statistics, University of Georgia, Athens, Georgia, USA.
Independent censoring is usually assumed in survival data analysis. However, dependent censoring, where the survival time is dependent on the censoring time, is often seen in real data applications. In this project, we model the vector of survival time and censoring time marginally through semiparametric heteroscedastic accelerated failure time models and model their association by the vector of errors in the model.
View Article and Find Full Text PDFStat Methods Med Res
November 2024
School of Mathematical Sciences, Queen Mary University of London, London, UK.
Covariate-adjusted response adaptive (CARA) designs are effective in increasing the expected number of patients receiving superior treatment in an ongoing clinical trial, given a patient's covariate profile. There has recently been extensive research on CARA designs with parametric distributional assumptions on patient responses. However, the range of applications for such designs becomes limited in real clinical trials.
View Article and Find Full Text PDFBiom J
December 2024
School of Mathematical and Physical Sciences, Macquarie University, Sydney, Australia.
Pharmacoepidemiol Drug Saf
November 2024
Epidemiology, IQVIA Deerfield, Deerfield, Illinois, USA.
Aim: This article provides an overview of time-to-event (TTE) analysis in pharmacoepidemiology.
Materials & Methods: The key concept of censoring is reviewed, including right-, left-, interval- and informative censoring. Simple descriptive statistics are explained, including the nonparametric estimation of the TTE distribution as per Kaplan-Meier method, as well as more complex TTE regression approaches, including the parametric Accelerated Failure Time (AFT) model and the semi-parametric Cox Proportional Hazards and Restricted Mean Survival Time (RMST) models.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!