Documenting Treatment Outcomes in Stuttering: Measuring Impairment, Disability, and Handicap

About the presenter: J. Scott Yaruss, Ph.D., CCC-SLP, is an assistant professor of Communication Science and Disorders at the University of Pittsburgh, where he teaches courses on fluency disorders and conducts research on the linguistic factors affecting the development of stuttering. Yaruss is also the co-director of the new Stuttering Center of Western Pennsylvania, a joint venture of the University of Pittsburgh and Children's Hospital of Pittsburgh, dedicated to research on stuttering, as well as treatment, education, and support for people who stutter, their families, and their clinicians. In conjunction with the Stuttering Center and other colleagues around the country, Yaruss has recently been conducting research on ways to document the outcomes of various approaches to treating stuttering in children and adults.

Documenting Treatment Outcomes in Stuttering:
Measuring Impairment, Disability, and Handicap

by J. Scott Yaruss
Pennsylvania, USA

One of the most challenging tasks facing speech-language pathologists (SLPs) today is the documentation and evaluation of treatment outcomes. Put simply, SLPs need to determine whether or not treatment actually works. This need is apparent across the broader spectrum of the health-related professions, in part due to the increasingly restrictive requirements of insurance companies and other third-party payers (e.g., Frattali, 1998a), and in part due to clients' increasing awareness of different treatment options. Even without the demands of payers and consumers, however, SLPs need to demonstrate that our treatments achieve their goals for ethical and professional reasons.

Although the need for treatment outcomes research is evident for the entire field of speech-language pathology, it is particularly apparent in the treatment of stuttering. In part, this is because of the numerous and disparate methods available for treating stuttering. Furthermore, the field has an unfortunate but rich history of promoting less-than-successful treatments (e.g., Bobrick, 1995). Thus, many clients, and clinicians as well, are left confused and frustrated about exactly what can be accomplished with the variety of stuttering treatment options that are available, and which technique is appropriate for a given individual who stutters.

Unfortunately, published reports on the efficacy of stuttering treatment can also be confusing. When reviewing existing literature on the outcomes of treatment for adults who stutter, it rapidly becomes apparent that the immediate results of some types of treatments have been more thoroughly documented, while other approaches have received less research attention (see reviews in Andrews, Guitar, & Howie, 1980; Bloodstein, 1995; Cordes, 1998; St. Louis & Westbrook, 1987). Specifically, there are numerous studies demonstrating the outcomes of various behaviorally based treatments for stuttering. There are considerably fewer studies, however, of integrated or "eclectic" treatments that involve both speech changes and counseling to address clients' reactions to stuttering. For example, of the 15 treatment studies conducted between 1980 and 1986 that were reviewed by St. Louis & Westbrook (1987), only four were reported to involve any type of counseling. As noted by Cordes (1998; see also Ingham & Cordes, in press), however, many of the treatment approaches that have been less thoroughly researched are also those that are frequently recommended to practicing clinicians in books and articles about stuttering. There are a number of very good reasons for these treatments to be recommended, even in the face of relatively less documentation of efficacy, such as the fact that these types of treatments focus a greater degree of attention on the client's feelings and other less tangible aspects of the disorder (Yaruss, 1998b). Thus, it appears that there is a compelling need to supplement the existing treatment outcomes literature in stuttering with additional research on those types of treatments that seek to bring about changes in the "intrinsic" (Manning, 1996) aspects of stuttering.

The Need for a Unifying Framework

Because of the considerable differences in various approaches to stuttering treatment, it would seem useful to have a unifying framework for categorizing these different types of treatments in a consistent and clinically relevant manner. Such a framework could facilitate the process of evaluating the outcomes of different treatment approaches by providing a common language that clinicians and researchers could use to describe their understanding of the client's complaint (Baer, 1990; see also Yaruss, 1998a, 1998b), as well as the nature of their treatments and the definition of success used in their programs.

One broad framework that can be applied to the problem of documenting treatment outcomes is the "perspectives" model being discussed by ASHA and the Special Interest Division in Fluency and Fluency Disorders (SID 4) in the recent Leadership conferences on stuttering treatment outcomes. According to this framework, the outcomes of treatment are viewed from a number of different perspectives, including: (a) the clinican's perspective, (b) the client's perspective, (c) the payer's perspective, and (d) society's perspective. As part of ASHA's process for developing a system for measuring the efficacy of stuttering treatments, the desired treatment outcomes have been identified from each of these perspectives and corresponding measurement scales are being developed to assess progress toward the desired goals (e.g., Ratner & Quesal, 1998).

Although this framework has the clear advantage of considering different points of view for defining successful treatment, it does not provide as much help for sorting out all of the different approaches to stuttering treatment whose outcomes must be studied. Accordingly, it seems reasonable to supplement this broader framework with a more detailed framework that breaks down the outcomes of treatment specifically from the client's perspective.

One conceptual framework that would seem to accomplish this goal is the World Health Organization's (WHO, 1980) International Classification of Impairments, Disabilities, and Handicaps (ICIDH). The ICIDH states that the consequences of a disorder can be viewed at three levels, as follows (WHO, 1980, pp. 25-29):

Impairment: ". . . any loss or abnormality of psychological, physiological, or anatomical structure or function."

Disability: ". . . any restriction of lack (resulting from an impairment) of ability to perform an activity in the manner or within the range considered normal for a human being."

Handicap: ". . . a disadvantage for a given individual, resulting from an impairment or a disability, that limits or prevents the fulfillment of a role that is normal (depending on age, sex, and social and cultural factors) for that individual."

According to researchers at the WHO Collaborating Center (WCC) for the ICIDH, the ICIDH is seen as quite distinct from the WHO's classification of the etiology of disorders described in the International Classification of Diseases, now in its tenth edition (ICD-10, WHO, 1992): "ICD covers causes and underlying conditions and ICIDH covers the consequences" (de Kleijn-de Vrankrijker, 1995, p. 109; see also Chamie, 1990; Halbertsma, 1995; Thuriaux, 1995). Because it focuses on the experiences of the individual exhibiting a disorder, the ICIDH seems well-suited for describing stuttering -- and, for documenting the outcomes of stuttering treatments that focus on improving the client's daily experiences and participation in life activities.

The ICIDH and Stuttering. Although the ICIDH concepts have been widely adopted across a variety of health-related fields, there has been some confusion about the use of the ICIDH terminology as applied to stuttering (see review in Yaruss, 1998a). Yaruss (1998a, 1998b) attempted to clarify the situation by developing a conceptual framework for discussing stuttering at various levels of the client's experience based on the ICIDH (see Fig. 1) and by offering definitions for the terms impairmentdisability, and handicap that relate specifically to stuttering. Put briefly, the presence of frequent speech disruptions that characterizes stuttering is, in and of itself, an impairment. The disability associated with the stuttering disorder can refer to reductions in the individual's ability to perform daily tasks, such as talking with others, using the telephone to complete tasks associated with a job, or communicating in certain situations. Finally, the handicap associated with stuttering might involve the reduction in an individual's ability to maintain his or her desired occupation or to fulfill his or her economic needs. (More specific examples of the impairments, disabilities, and handicaps that might be seen in an individual who stutters can be found in Yaruss, 1998a, 1998b). It is important to note that not all individuals who stutter will experience disabilities or handicaps because of their underlying impairment in speech fluency; and that the likelihood that they will experience disabilities or handicaps is mediated, in large part, by their own affective, behaviors, and cognitive reactions to their stuttering, as well as the reactions of those in their environments. Each of these components is reflected in the conceptual framework shown in Figure 1.

Figure 1. Schematic version of Yaruss's (1998a) conceptual framework for viewing the speaker's experience of the stuttering disorder.


The ICIDH and treatment outcomes research. The primary benefit of the model presented above is that it helps to delineate various levels of measurement associated with the components of different treatment approaches. For example, many authors (e.g., Conture, 1997; Conture & Yaruss, 1993; Costello & Ingham, 1984; Curlee, 1993; Ingham & Cordes, 1997; Yaruss, 1997, 1998c) have discussed the process of assessing various aspects of the stuttering impairment (e.g., measures of stuttering frequency, duration, type, and severity; impact of stuttering on speaking rate; audible and visible characteristics of stuttering, etc.). In addition, there are a number of testing instruments that assess the affective, behavioral, and cognitive reactions to stuttering (e.g., Andrews & Cutler, 1974; Brutten & Shoemaker, 1974; Craig, Franklin, & Andrews, 1984; Johnson, Darley, & Spriestersbach, 1952; Ornstein & Manning, 1985; Perkins, 1981). These levels of measurement have been applied successfully and meaningfully in a number of treatment outcomes studies for various behavioral treatments (e.g., Boberg & Kully, 1994).

On the other hand, there are few, if any, instruments that are specifically designed to assess changes in disability or handicap in individuals receiving stuttering treatment. For example, there are presently no standardized or criterion-referenced tests for assessing whether individuals who stutter are able to perform activities following treatment that they were unable to perform prior to treatment (i.e., assessing any reduction in disability), or whether individuals experience fewer disadvantages or improved quality of life following treatment than before treatment (i.e., assessing any reduction of handicap). The lack of established testing instruments for evaluating these aspects of treatment complicates the already difficult task of documenting treatment outcomes and assessing treatment efficacy, for researchers aiming to document the outcomes of such treatments lack the measurement instruments necessary to complete that documentation. It is clear, then, that there is a need for new measurement instruments designed to assess changes in disability and handicap experienced by individuals who stutter.

Measuring Disability and Handicap in People Who Stutter

In an attempt to improve the ability of clinicians to document changes in their clients in the disability and handicap domains, the present author and colleagues have been developing and testing a series of measurement instruments that focus on aspects of disability and handicap. Specifically, we are attempting to measure functional status (i.e., the ability to perform basic tasks associated with daily living or the completion of occupational duties; disability level) and quality of life (i.e., the overall experience of disadvantages or limitations in the fulfillment of social, economic, or occupational roles; handicap level). In addition, we have been developing an additional instrument designed to assess the speaker's reactions to stuttering in the affective, behavioral, and cognitive domains that is specifically based in the context of the conceptual framework presented above.

Each instrument involves a series of rating scales -- some agreement scales, some frequency scales -- designed to assess various aspects of the speaker's experience of the stuttering disorder. To date, the experimental testing instruments have been sent to approximately 75 people who stutter. Subjects were current or former clients of the Northwestern University or Western Illinois University clinics, or participants in National Stuttering Project chapters in the Chicagoland area. In addition to the three testing instruments, subjects were also sent a detailed demographic questionnaire (attached) that collected information about the subjects' prior treatment, as well as an instrument evaluation form that sought subjects' feedback about the questionnaires. Finally, subjects were also sent the S-24 communication attitudes inventory (Andrews & Cutler, 1974) to assess aspects of the concurrent validity of the experimental instruments. At present, approximately 35 questionnaires have been returned.

Following are some brief details about each of the testing instruments. Additional detail about these developing instruments will be presented in a miniseminar at the upcoming ASHA conference in San Antonio. (Copies of the current drafts of the measurement instruments are available by contacting the author.)

Reactions. The first instrument, Speaker's Reactions to Stuttering, contains four sections, each examining a different aspect of the way people who stutter might react to the fact that they stutter. Part I lists several emotions that people who stutter might feel, such as embarrassment or frustration, and asks respondents to rate how often the experience these emotions when they think about their stuttering. Part II focuses on specific behaviors that people who stutter might exhibit, such as avoidance, tension, or physical struggle that often characterized advanced stuttering. Part III is designed to assess the way people who stutter think about themselves and their speaking abilities in general by assessing the degree to which respondents ascribe to certain cognitive statements about speaking, stuttering, and people who do and do not stutter. Part IV examines attitudes toward a variety of items related to speaking and stuttering by combining the affective, behavioral, and cognitive domains into broader attitudinal statements.

In many ways, the items on this scale are similar to those found in existing attitudes inventories (e.g., Andrews & Cutler, 1974); however, in the present testing instrument, considerable effort has been made to separate affective, behavioral, and cognitive factors (termed feelings, behaviors, and thoughts on the instrument, respectively) to allow the clinician to examine these factors individually (e.g., Watson, 1988). Furthermore, an attempt has been made to move away from situation-based items (e.g., Ornstein & Manning, 1985; Watson, 1988), in part based on criticisms that such items merely reflect the client's level of fluency in those situations (Ulliana & Ingham, 1984).

Functional Status. The second instrument, Functional Communication and Stuttering, is designed to explore how much stuttering interferes with speakers' ability to perform certain tasks associated with daily living or functioning in the school or workplace. Note that this tool is not focusing on the speakers' fluency while performing these tasks, but how likely the speakers are to attempt to do them, regardless of how fluent they are. For example, many people who stutter avoid using the telephone. In this case, we are interested in whether clients will use the telephone at all (i.e., the degree of disability), rather than how fluent they will be when they do use the phone (i.e., the degree of impairment). The instrument was modeled after the ASHA Functional Assessment of Communication Skills for Adults (ASHA FACS; Frattali, Thompson, Holland, Wohl, & Ferketic, 1995) and other functional status instruments (reviewed in Frattali, 1998b), that highlight the importance of assessing clients' functional communication abilities.

Quality of Life. The third instrument, Quality of Life and Stuttering, was designed to examine the impact that stuttering has on speakers' ability to pursue their life goals in a variety of different domains, such as social interaction, economic independence, etc. (i.e., the handicap resulting from stuttering). Definitions for quality of life and handicap were based on the World Health Organization Quality of Life group (WHOQOL, 1995). Quality of Life scales are typically focused on more debilitating types of disorders than stuttering (e.g., chronic pain, cancer). Still, by examining the domains assessed in other Quality of Life instruments (e.g., Kaplan, Anderson, & Ganiats, 1993; McEwan, 1993), it was possible to select a set of items that related to stuttering and communication (see also Bergner, 1989; Schipper, Clinch, & Powell, 1990; Schumaker, Anderson, & Czajkowski, 1990; Testa & Simonson, 1996), including social, occupational, psychological, health-related, and spiritual impact, as well as overall satisfaction with communication abilities.

By combining the results of these three new testing instruments with existing measures of the stuttering impairment, it is hoped that clinical researchers interested in documenting the outcomes of various approaches for treating stuttering will have the tools necessary to satisfy the increasing demands of payers and consumers for determining the efficacy of the treatments we recommend.


In summary, there is much work to be done to improve the documentation of the outcomes for various approaches to stuttering treatments. The difficulty of the tasks stems not just from the complications of treatment outcomes research itself, but also from the fact that stuttering is a complicated, multi-faceted disorder that is viewed different ways by different people. This paper has reviewed a conceptual framework that is based on a widely used framework for discussing the consequences of disorders on individual's lives and suggested that the framework can be used to guide the process of evaluating treatment outcomes. In addition, the paper has highlighted certain aspects of treatment where documentation of outcomes has generally been inadequate and proposed new ways to measure the results of treatment in the context of the ICIDH framework. It is hoped that the framework and the resulting measurement instruments will generate discussion about how to appropriately document the results of treatment, both for demonstrating the efficacy of treatment and, ultimately, for improving those treatments in order to reduce the likelihood that the stuttering impairment will result in significant disabilities or handicaps for the clients we treat.

Author Note

The author is grateful to Dr. Robert Quesal for his collaboration in developing and evaluating the measurement instruments, as well as to Amy King and Michelle Schaffner for their participation in the projects. Questions about the measurement instruments or correspondence regarding this article should be directed to: J. Scott Yaruss, The University of Pittsburgh, 4033 Forbes Tower, Pittsburgh, PA 15260. Email:


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