Published by the Foundation for Open Access Statistics Editors-in-chief: Bettina Grün, Torsten Hothorn, Edzer Pebesma, Achim Zeileis    ISSN 1548-7660; CODEN JSSOBK
Authors: Furio Camillo, Ida D'Attoma
Title: %GI: A SAS Macro for Measuring and Testing Global Imbalance of Covariates within Subgroups
Abstract: The global imbalance (GI) measure is a way for checking balance of baseline covariates that confound efforts to draw valid conclusions about treatment effects on outcomes of interest. In addition, GI is tested by means of a multivariate test. The GI measure and its test overcome some limitations of the common way for assessing the presence of imbalance in observed covariates that were discussed in D'Attoma and Camillo (2011). A user written SAS macro called %GI, to simultaneously measure and test global imbalance of baseline covariates is described. Furthermore, %GI also assesses global imbalance by subgroups obtained through several matching or classification methods (e.g., cluster analysis, propensity score subclassification, Rosenbaum and Rubin 1984), no matter how many groups are examined. %GI works with mixed categorical, ordinal and continuous covariates. Continuous baseline covariates need to be split into categories. It also works in the multi-treatment case. The use of the %GI macro will be illustrated using two artificial examples.

Page views:: 3250. Submitted: 2011-11-15. Published: 2012-11-13.
Paper: %GI: A SAS Macro for Measuring and Testing Global Imbalance of Covariates within Subgroups     Download PDF (Downloads: 3445)
Supplements: SAS macro source code Download (Downloads: 746; 4KB) SAS example data and code for the binary treatment case Download (Downloads: 716; 45KB) SAS example data and code for the multi-treatment case Download (Downloads: 765; 407KB)

DOI: 10.18637/jss.v051.c01

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Paper: Creative Commons Attribution 3.0 Unported License
Code: GNU General Public License (at least one of version 2 or version 3) or a GPL-compatible license.