Tests of marginal homogeneity and special cases1. (14th June 2013)

• Record Type: Journal Article
• Authors: Dunnigan, Keith
• Is Part Of: Pharmaceutical statistics. Volume 12:Number 4(2013:Jul./Aug.)
• Page Start: 213
• Page End: 216
• Publication Date: 2013-06-14
• Subjects: Pharmacy -- Statistical methods -- Periodicals; Pharmacy -- Statistics -- Periodicals; 615.10727
• DOI: 10.1002/pst.1573
• Languages: English
• ISSNs: 1539-1604

Abstract

<abstract abstract-type="main" id="pst1573-abs-0001"> <title>Abstract</title> <p>The analysis of two‐way contingency tables is common in clinical studies. In addition to summary counts and percentages, statistical tests or summary measures are often desired. If the data can be viewed as two categorical measurements on the same experimental unit (matched pair data) then a test of marginal homogeneity may be appropriate. The most common clinical example is the so called 'shift table' whereby a quantity is tested for change between two time points. The two principal marginal homogeneity tests are the Stuart Maxwell and Bhapkar tests. At present, <sc>SAS</sc> software does not compute either test directly (for tables with more than two categories) and a programmatic solution is required. Two examples of programmatic <sc>SAS</sc> code are found in the current literature. Although accurate in most instances, they fail to produce output for certain tables ('special cases'). After summarizing the mathematics behind the two tests, a <sc>SAS</sc> macro is presented, which produces correct output for all tables. Finally, several examples are coded and presented with resultant output. Copyright © 2013 John Wiley &amp; Sons, Ltd.</p> </abstract>