65th ISI World Statistics Congress 2025

65th ISI World Statistics Congress 2025

Time-to-Event Analysis with Unknown Time Origins via Longitudinal Biomarker Registration

Author

WG
Wensheng Guo

Co-author

  • S
    Sarah Ratcliffe
  • T
    Tianhao Wang

Conference

65th ISI World Statistics Congress 2025

Format: IPS Abstract - WSC 2025

Keywords: "statistical, functional-data-analysis

Session: IPS 917 - Harnessing the Power of Functional Data and Machine Learning in Biomedical Research

Tuesday 7 October 2 p.m. - 3:40 p.m. (Europe/Amsterdam)

Abstract

In observational studies, the time origin of interest for time-to-event analysis is often unknown, such as the time of disease onset. Using the study entry as time zero often leads to misleading results. Existing approaches to estimating the time origins are commonly built on extrapolating a parametric longitudinal model, which rely on rigid assumptions that can lead to biased inferences. In this paper, we introduce a flexible semiparametric curve registration model. It assumes the longitudinal trajectories follow a flexible common shape function with person-specific disease progression pattern characterized by a random curve registration function, which is further used to model the unknown time origin as a random start time. This random time is used as a link to jointly model the longitudinal and survival data where the unknown time origins are integrated out in the joint likelihood function, which facilitates unbiased and consistent estimation. Simulation studies and two real data applications demonstrate the effectiveness of this new approach.