Date of Award


Document Type


Degree Name



Quantitative Research Methods

First Advisor

Antonio Olmos, Ph.D.

Second Advisor

Michael Faragher

Third Advisor

Kathy Green

Fourth Advisor

Ruth Chao


Counseling, Problem gambling, Propensity scores


This study applied a multi-group form of propensity score analysis to the study of outcomes related to problem gambling treatment. Across various treatment settings, it is often unfeasible or unethical to randomly assign participants to different treatment conditions, particularly when one of the conditions involves not receiving treatment. Additionally, evaluative practices often involve assessing outcomes from a primarily treatment focused setting, in which case clients are likely not randomly assigned to treatment. Consequently, where randomization does not exist, methods such as propensity score matching need to be implemented to separate what part of the observed outcomes is attributable to treatment and what part may be due to preexisting differences between the comparison groups. Traditional propensity score matching procedures involve matching and comparing across two groups, typically a treatment and a control group. This study applied newly developed methods for matching participants on propensity scores across three groups.

This study uses archival treatment data to compare three psychotherapeutic problem gambling treatments (cognitive-behavioral therapy, solution-focused brief therapy, and time-limited dynamic psychotherapy) where outcomes were likely influenced by self-selection of form of therapy. Specifically, this study looked at whether participants improved their psychosocial functioning through five weeks of treatment, and, if so, are the three forms of treatment equally effective.

The results of this study support the utility of multi-group propensity score matching procedures. Covariate imbalance was improved through each of the four implemented matching procedures, though two of the matching procedures (caliper matching and 3:2:n matching) were more effective in reducing bias. The matching procedures also indicate that there may be a difference between treatment effects that was not observed through an unmatched analysis. The matching procedures consistently estimated the treatment effect for cognitive-behavioral therapy to be greater than that of the time-limited dynamic psychotherapy. This difference was found to be statistically significant on two of the four matching methods. Limitations of this study and recommendations for future research are also discussed.

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.


Received from ProQuest

Rights holder

Adam David Soberay

File size

198 p.

File format





Statistics, Counseling psychology