Overall Assessment of The Speaker’s Experience of Stuttering (OASES)

J. Scott Yaruss1 and Robert W. QUESAL2
1Deportment of Communication Sciences and Disorders, University of Pittsburgh, Pittsburgh, PA
2C0mmunication Sciences and Disorders, Western Illinois University, Macomb, IL 61455, USA


Recent years have seen a renewed interest in measuring treatment outcomes, particularly for broad-based treatment approaches that attempt to achieve changes in a speal<er’s overall communication ability rather than focusing solely or primarily on gains in fluency. Unfortunately, prior attempts to document such treatment outcomes have been hindered by a relative lack of reliable instruments for assessing real-world outcomes. This paper describes the development of a new measurement instrument for assessing several aspects of the speaker’s experience of stuttering, including fluency, personal and environmental reactions, difficulties with functional communication, and the impact of stuttering on the speaker’s quality of life. Preliminary data demonstrating the value of the instrument are presented for 4 individuals who have recently completed a broad-based treatment program.

Many authors have commented on the need for more empirical evidence about treatment outcomes in stuttering. Numerous studies have demonstrated that fluency shaping approaches, such as prolonged speech and response contingent stimulation, can reduce the frequency of stuttering (at least in the therapy room). Unfortunately, there is considerably less published evidence about the efficacy of approaches based on stuttering modification or desensitization that are designed to improve a speaker’s overall communication ability.

Given the relative lack of empirical evidence for some stuttering treatment approaches, clinicians and researchers are left with a simple choice: either restrict the selection of treatment approaches to include only those for which published evidence is already available (so-called “evidence-based practice’) or identify other approaches that appear, through anecdotal evidence and clinical experience, to have validity, then evaluate the outcomes of those approaches to create the necessary database of empirical support. A review of the treatment literature in stuttering (Cordes, 1998) shows that even without the requisite evidence, many clinicians and people who stutter feel that broad-based approaches do provide the preferred outcome, at least for some people who stutter (Yaruss, et al., 2002; Yaruss et al., 2002). Because of the remarkable strength of the anecdotal evidence for stuttering modification and eclectic approaches to stuttering, therefore, the present authors have selected a strategy based on this second option - that is, to continue using broad-based approaches to treatment while trying to demonstrate the value of these approaches through outcomes research.

Unfortunately, there is a significant roadblock to demonstrating the efficacy of broad-based approaches to stuttering therapy. Although treatments focused only (or mainly) on the frequency of stuttering have traditionally been “assessed” based only (or mainly) on the reduction in stuttering pre- vs. post-treatment, such a limited evaluation strategy is insufficient for demonstrating changes associated with broad-based treatment approaches. There are a number of reasons for this. First, if treatment is aimed at making changes in all aspects of a speaker’s communication (including fluency and willingness to communicate, ability to stutter easily and with less physical tension, improved communication attitudes, etc.), then it is appropriate - and, indeed, necessary - to measure all of those changes, not just the changes that are apparent in one easily observed domain (stuttering frequency). Furthermore, reduction in the frequency of stuttering may not actually be the goal of therapy. Often, a client who is avoiding speaking or experiencing significant tension and struggle during stuttering may have a goal of actually stuttering more, as a way of bringing the stuttering outto make it less physically tense or less severe. In this case, simply counting stuttered syllables will give an inaccurate representation of the changes associated with treatment. Such broad-based, complex goals cannot adequately be captured by existing treatment outcomes evaluation strategies.

There is a need, therefore, for a method for evaluating all of the outcomes of stuttering therapy. A number of instruments have previously been presented for assessing the frequency of stuttering and the attitudes of the speaker toward speaking ability and stuttering. Examples include the Iowa Scale of Attitude Toward Stuttering (Ammons & Johnson, 1944), the Erickson Scale (Erickson, 1969), the S-24 scale (Andrews & Cutler, 1974), the Perceptions of Stuttering Inventory (Woolf, 1967), etc. Many of these instruments have been used in treatment outcomes research (e. g., Boberg & Kully, 1994); however, as noted above, there has not been sufficient research using these instruments for broad-based approaches to treatment. Furthermore, there is no single instrument available at present that examines the breadth of the stuttering disorder from the speaker’s perspective.

For the -past several years, the present authors have been working on developing just such an instrument. Currently titled the “Overall Assessment of the Speaker’s Experience of Stuttering (OASES),” this instrument has been designed to examine all aspects of the stuttering disorder, from the perspective of the speaker. This paper-and-pencil instrument is based on the framework of the World Health Organization’s original International Classification of Impairment, Disability, and Handicap (ICIDH, WHO, 1980), as well as the recent revision, the International Classification of Functioning, Disability, and Health (ICF, WHO, 2001). i

The applicability of these frameworks to stuttering and the evaluation of stuttering treatment outcomes was discussed by Yaruss (1998, 2001) and Yaruss & Quesal (in press). In essence, it has been demonstrated that these frameworks provide a means for discussing all aspects of the stuttering disorder - not just the observable speech fluency. More specifically, the ICF is designed to capture several aspects of the human experience of health and disablement, regardless of the specific health condition, including: (a) the possible impairments that may occur in body structure or function, (b) the resulting limitations in an individual’s ability to conduct daily activities or the restrictions the individual may experience in the ability to participate in life. Note that these components of the model are generally analogous to the impairment, disability, and handicap classifications described by the WHO’s original ICIDH model. The new ICF supplements this information, however, with a description of contextual factors such as: (a) personal factors (such as how the individual responds to or copes with health experiences), and (b) environmental factors that may help or hinder the individual’s ability to live with impairments. Because the he ICF attempts to provide a broad-based description of life experiences, it is a particularly useful framework for the assessment of broad- based treatment outcomes in stuttering. In addition, the instrument can also be used to gain helpful insights into the treatment process by highlighting specific issues the client may wish to address in treatment.

Using the ICF as a starting point then, then, the OASES was designed to include sections for assessing: (a) a speaker’s se1f-reported speech fluency (impairment), (b) the affective, behavioral, and cognitive reactions a speaker may have to stuttering, (c) the impact of stuttering on the speaker’s ability to communicate in daily situations (including the impact of different situations), and (d) consequences of the stuttering for the speaker’s overall quality of life. Earlier versions of the OASES were based on three separate trial instruments (one for assessing the speaker’s affective, behavioral, and cognitive reactions to stuttering; one for assessing the difficulties with functional communication, and one for assessing the impact of stuttering on the speaker’s overall quality of life). Preliminary versions were administered to more than 250 people who stutter recruited from the National Stuttering Association so the distribution of scores could be evaluated for each item, and analyses were performed to ensure reliability of the instrument. The final version of the OASES contains a total of 100 items, divided into 4 sections containing a series of 5-point Likert scales and agreement scales. The minimum score on the instrument (if all items are answered) is 100, and the maximum score is 500. For each item, higher scores indicate a greater severity or more negative consequence of stuttering, so the higher the overall score, the greater the impact of stuttering on the speaker’s life.

To demonstrate the potential value for using the OASES in treatment outcomes research, the instrument is currently being administered to a series of adults who stutter who are participating in a broad-based treatment program. Participants are administered the OASES prior to the initial diagnostic evaluation session, then again at the conclusion of treatment. The OASES will again be administered approximately 6 months after the conclusion of treatment.

Preliminary results from four participants in this pilot study are shown in Figure 1. These results demonstrate changes in OASES scores seen from the beginning to end of treatment for two 21-year-old females, a 23-year-old male, and a 27-year-old male who participate in treatment during summer, 2003. The stacked-bar charts show changes for each of the four components of the OASES (general information, reactions to stuttering, functional communication, and quality of life) for each of the four participants. As noted above, the minimum score on this instrument is 100 (if all items are answered), so it is apparent that the participants are all nearing minimal levels of impact from their stuttering by the end of treatment.


Figure l. OASES component and total scores for 4 participants in a broad-based treatment program.

Future studies will be needed, of course, to evaluate the durability of this measure. For now, however, these results demonstrate that it should be possible to use the OASES as a means of documenting change speakers undergo in their overall experience of the stuttering disorder.

As further information of this type is collected by clinicians and researchers, and as this information makes its way into the research base for our field, it should become easier to evaluate and compare the outcomes of a variety of different treatment approaches and, ultimately, to address the present concern about the lack of empirical findings regarding stuttering treatment efficacy. This should also minimize calls for clinicians to adhere strictly to one type of therapy over another due simply to dogmatic bias about preferred treatment outcomes, and allow treatment decisions to be made from an appropriately broad-based and comprehensive literature.


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Yaruss, J .S., Quesal, R.W., Reeves, L., Molt, L., Kluetz, B., Caruso, A.J., Lewis, F., & McClure, J .A. (2002) Speech treatment and support group experiences of people who participate in the National Stuttering Association. Journal of Fluency Disorders, 27, 115-135.
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