Clinical and Methodological Utility of a Composite Outcome Measure for Alcohol Treatment Research

Authors


  • Preparation of this article was supported by a series of grants from the National Institute on Alcohol Abuse and Alcoholism (NIAAA) as part of the Cooperative Agreement on Matching Alcohol Treatments to Client Heterogeneity (Project MATCH), the Milwaukee Clinical Research Unit, Grants RO1-AA08442-09 and RO1-AA08442-06, Supplement 1. However, the ideas and views herein are solely the responsibility of the authors and do not necessarily reflect the official views of the NIAAA.

Allen Zweben, DSW, Center for Addiction and Behavioral Health Research, University of Wisconsin-Milwaukee, P.O. Box 786, Milwaukee, WI 53201-0786; Fax: 414-229-5311; E-mail: zweben@uwm.edu

Abstract

Background: How to capture different response patterns resulting from alcohol treatment has been a troublesome issue for alcohol researchers. A composite measure is one approach to capturing multiple treatment outcomes among diverse client populations. This article provides the rationale, development, and work conducted thus far on the composite outcome index and discusses the clinical utility of the measure.

Methods: With the use of Project MATCH data, the composite outcome measure was examined in relation to self-reported alcohol consumption and alcohol problems and biological markers as well as in relation to other areas of functioning, such as psychiatric dysfunction and quality of life. Also, for assessing the stability of the measure, different composite outcomes statuses were assessed over time.

Results: Individuals with better scores on composite outcome index had fewer percent days abstinent, consumed more alcohol when they drank, had a greater number of alcohol problems, and evidenced higher blood levels as measured by γ-glutamyltranspeptidase and carbohydrate-deficient transferrin. Individuals with poorer composite outcome statuses had poorer social and behavioral role functioning and mental and physical health–related quality of life. Findings on short- and long-term composite outcome statuses revealed that only a minority of clients (30%) sustained a remitted status (i.e., abstinent or moderate drinking without problems) over the 1-year follow-up, and fully 70% of the clients had reached a nonremitted status (i.e., heavy drinking and/or problems) on the composite measure at one or more time points during the 12-month follow-up.

Conclusions: The composite outcome index could be used usefully along with singular measures of consumption to obtain a more complete picture of what has occurred among clients posttreatment. Future work will involve the testing of the composite outcome index with other client populations and/or different treatments to further our understanding of the varying response patterns found among alcohol-dependent clients.

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