JSM 2015 Preliminary Program

Online Program Home
My Program

Abstract Details

Activity Number: 367
Type: Contributed
Date/Time: Tuesday, August 11, 2015 : 10:30 AM to 12:20 PM
Sponsor: Biometrics Section
Abstract #315853
Title: Proportional Hazards Regression Modeling with Dichotomized Longitudinal Biomarkers Measured with Error
Author(s): Rong Fu* and Peter B. Gilbert
Companies: University of Washington and Fred Hutchinson Cancer Research Center
Keywords: Longitudinal biomarkers ; Measurement error ; Proportional hazards model ; Random effects model
Abstract:

In cohort studies and clinical trials, a common objective is to assess time-varying longitudinal biomarkers as correlates of the instantaneous hazard of a study endpoint. We are interested in studying a typical practice where biomarker levels are dichotomized at fixed thresholds. The biomarker values are often measured intermittently and with error, which undermines the validity/asymptotic consistency from the standard Cox model. We address this problem via joint models. The underlying continuous biomarker trajectories are characterized by random effects models, while the relationship between the dichotomized trajectories and the instantaneous risk is characterized by a Cox model. The estimation is made via the risk set regression calibration method to reduce the asymptotic bias due to measurement errors. We compared our method to the naive two-stage method through simulation studies under various event rates and numbers of measuring time points. Our method retains very small level of bias in most settings. The application to real data is illustrated on the ACTG 175 antiretroviral therapy trial.


Authors who are presenting talks have a * after their name.

Back to the full JSM 2015 program





For program information, contact the JSM Registration Department or phone (888) 231-3473.

For Professional Development information, contact the Education Department.

The views expressed here are those of the individual authors and not necessarily those of the JSM sponsors, their officers, or their staff.

2015 JSM Online Program Home