Publication Abstract

Authors: Wang X, Baldwin S, Wainer H, Bradlow ET, Reeve BB, Smith AW, Bellizzi KM, Baumgartner KB

Title: Using Testlet Response Theory to analyze data from a survey of attitude change among breast cancer survivors.

Journal: Stat Med 29(19):2028-44

Date: 2010 Aug 30

Abstract: In this paper we examine alternative measurement models for fitting data from health surveys. We show why a testlet-based latent trait model that includes covariate information, embedded within a fully Bayesian framework, can allow multiple simultaneous inferences and aid interpretation. We illustrate our approach with a survey of breast cancer survivors that reveals how the attitudes of those patients change after diagnosis toward a focus on appreciating the here-and-now, and away from consideration of longer-term goals. Using the covariate information, we also show the extent to which individual-level variables such as race, age and Tamoxifen treatment are related to a patient's change in attitude.The major contribution of this research is to demonstrate the use of a hierarchical Bayesian IRT model with covariates in this application area; hence a novel case study, and one that is certainly closely aligned with but distinct from the educational testing applications that have made IRT the dominant test scoring model.