This is the program for the 2010 Joint Statistical Meetings in Vancouver, British Columbia.

Abstract Details

Activity Number: 360
Type: Contributed
Date/Time: Tuesday, August 3, 2010 : 10:30 AM to 12:20 PM
Sponsor: Biometrics Section
Abstract - #306870
Title: Improving Small-Sample Inference in Group-Randomized Trials with Binary Outcomes
Author(s): Philip Westgate*+ and Thomas Braun
Companies: University of Michigan and University of Michigan
Address: 648 Manor Dr., Ann Arbor, MI, 48105,
Keywords: Group Randomized Trials ; Binary Outcomes ; Quasi-Likelihood ; Wald Statistic

Group Randomized Trials typically randomize a small number of clusters composed of a large number of subjects, resulting in over-dispersion quantified using the intra-cluster correlation coefficient (ICC). When subject-level outcomes are binary, modeling can be done using quasi-likelihood with a logistic link. In this setting, the Wald statistic used to test for a treatment effect, which asymptotically has a standard normal distribution, may have a variance less than one, resulting in a test size smaller than its nominal value. When the ICC is known, we develop a method for adjusting the estimated standard error such that the Wald statistic approximately has a standard normal distribution. We also propose a way to resolve non-nominal test sizes when the ICC is estimated. Through simulation results covering a variety of realistic settings, we examine the performance of our methods.

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 2010 program

2010 JSM Online Program Home

For information, contact or phone (888) 231-3473.

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