JSM 2012 Home

JSM 2012 Online Program

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

Online Program Home

Abstract Details

Activity Number: 670
Type: Contributed
Date/Time: Thursday, August 2, 2012 : 10:30 AM to 12:20 PM
Sponsor: Social Statistics Section
Abstract - #305612
Title: Mediation Analysis Based on Propensity Scores
Author(s): Yeying Zhu*+ and Debashis Ghosh and Donna Coffman
Companies: Penn State University and Penn State University and Penn State University
Address: 600 Toftrees Ave, State College, PA, , United States
Keywords: causal inference ; generalized boosting ; mediation analysis ; propensity scores ; sequential ignorability
Abstract:

In clinical trials, many researchers are interested in examining whether a randomized treatment or intervention may affect the outcome through an intermediate factor. Traditional mediation analysis (Baron and Kenny, 1986) applies structure equation modeling (SEM) and decomposes the intent-to-treat (ITT) effect into direct and indirect effects. More recent approaches interpret the mediation effects as controlled effects (Robins and Greenland, 1992), natural effects (Pearl, 2001), and principal stratification effects (Frangakis and Rubin, 2002), and so forth. In practice, there often exist confounders, pre-treatment covariates that jointly influence the mediator and the outcome. We propose propensity-score-based methods to reduce the dimensionality of confounders under the sequential ignorability assumption. We assess the proposed methods through simulation studies. Furthermore, we show that combining machine learning algorithms (such as a generalized boosting method) and logistic regression to estimate propensity scores can be more accurate and flexible in mediation analysis, compared to logistic regression only.


The address information is for the authors that have a + after their name.
Authors who are presenting talks have a * after their name.

Back to the full JSM 2012 program




2012 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.