JSM 2013 Home
Online Program Home
My Program

Abstract Details

Activity Number: 438
Type: Contributed
Date/Time: Tuesday, August 6, 2013 : 2:00 PM to 3:50 PM
Sponsor: Health Policy Statistics Section
Abstract - #307773
Title: Unbiased Estimation in the Presence of Left-Truncation and Time-Dependent Exposures
Author(s): Alex Bliu*+ and Erica E. M. Moodie
Companies: McGill University and McGill University
Keywords: causal inference ; survival analysis ; left-truncation ; multiple imputation ; cohort studies ; chronic diseases
Abstract:

In many cohort studies of chronic diseases, the time on the study does not coincide with the time of disease onset, and treatment may precede cohort entry. In time-to-event analyses, the choice of time scale may have a significant impact on the estimates and their precision. Using time on the study instead of time since disease onset as the time scale may be subject to different sources of bias including left truncation. While appropriate choice of time scale and modification of the risk sets typically eliminate bias due to left-truncation when subjects cannot be exposed prior to cohort entry, to date no methods exist to address the problem of subjects exposed to time-varying treatments which precede cohort entry. Motivated by the study of the effect of ART interruption on liver fibrosis progression in co-infected adults, we examine the impact of left truncation and exposure prior to cohort entry on the treatment effect estimator defined by a marginal structural Cox proportional hazard model and propose a new, imputation-based approach to address this significant challenge.


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

Back to the full JSM 2013 program




2013 JSM Online Program Home

For information, contact jsm@amstat.org or phone (888) 231-3473.

If you have questions about the Continuing Education program, please 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.

ASA Meetings Department  •  732 North Washington Street, Alexandria, VA 22314  •  (703) 684-1221  •  meetings@amstat.org
Copyright © American Statistical Association.