JSM 2015 Preliminary Program

Online Program Home
My Program

Abstract Details

Activity Number: 327
Type: Invited
Date/Time: Tuesday, August 11, 2015 : 10:30 AM to 12:20 PM
Sponsor: Biometrics Section
Abstract #314198
Title: Analysis of Semiparametric Regression Model for Longitudinal Data with Censored Time Origin
Author(s): Yanqing Sun* and Qiong Shou and Peter B. Gilbert and Xiyuan Qian
Companies: The University of North Carolina at Charlotte and Merck and Fred Hutchinson Cancer Research Center and East China University of Science and Technology
Keywords: Censored event time ; Missing data ; Profile local linear estimation ; Repeated measurements ; the STEP trial ; Weighted least squares
Abstract:

Statistical analysis of longitudinal data often involves modelling treatment effects on clinically relevant longitudinal biomarkers since an initial event (the time origin). This research is motivated by the need to assess the HIV vaccine effect on the post HIV infection longitudinal biomarkers when the exact time of infection may be unknown. We investigate the problem under the semiparametric additive time-varying coefficient model where the influences of some covariates vary nonparametrically with time while the effects of the other covariates remain constant. The weighted profile least squares estimators are developed for the unknown parameters as well as for the nonparametric coefficient functions. The method uses the expectation maximization approach to deal with the censored time origin. The asymptotic properties of both the parametric and nonparametric estimators are derived and the consistent estimates of the asymptotic variances are given. The numerical simulations are conducted to examine finite sample properties of the proposed estimators. The method is applied to a real data from the STEP study with MITT cases.


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