Efficacy of the Modifying Phonation Intervals (MPI) Stuttering Treatment Program With Adults Who Stutter.

PURPOSE: This study compared a new adult stuttering treatment program (Modifying Phonation Intervals, or MPI) with the standard of care for reducing stuttered speech in adults (prolonged speech). METHOD: Twenty-seven adults who stutter were assigned to either MPI or prolonged speech treatment, both of which used similar infrastructures. Speech and related variables were assessed in 3 within-clinic and 3 beyond-clinic speaking situations for participants who successfully completed all treatment phases. RESULTS: At transfer, maintenance, and follow-up, the speech of 14 participants who successfully completed treatment was similar to that of normally fluent adults. Successful participants also showed increased self-identification as a "normal speaker," decreased self-identification as a "stutterer," reduced short intervals of phonation, and some increased use of longer duration phonation intervals. Eleven successful participants received the MPI treatment, and 3 received the prolonged speech treatment. CONCLUSIONS: Outcomes for successful participants were very similar for the 2 treatments. The much larger proportion of successful participants in the MPI group, however, combined with the predictive value of specific changes in PI durations suggest that MPI treatment was relatively more effective at assisting clients to identify and change the specific speech behaviors that are associated with successful treatment of stuttered speech in adults.

Regional brain activity change predicts responsiveness to treatment for stuttering in adults.

Developmental stuttering is known to be associated with aberrant brain activity, but there is no evidence that this knowledge has benefited stuttering treatment. This study investigated whether brain activity could predict progress during stuttering treatment for 21 dextral adults who stutter (AWS). They received one of two treatment programs that included periodic H2(15)O PET scanning (during oral reading, monologue, and eyes-closed rest conditions). All participants successfully completed an initial treatment phase and then entered a phase designed to transfer treatment gains; 9/21 failed to complete this latter phase. The 12 pass and 9 fail participants were similar on speech and neural system variables before treatment, and similar in speech performance after the initial phase of their treatment. At the end of the initial treatment phase, however, decreased activation within a single region, L. putamen, in all 3 scanning conditions was highly predictive of successful treatment progress.

A welfare economic approach to measure outcomes in stuttering: comparing willingness to pay and quality adjusted life years.

PURPOSE: The purpose of this study was to compare two welfare outcome measures, willingness to pay (WTP) and quality adjusted life years (QALYs) gained, to measure outcomes in stuttering. METHOD: Seventy-eight adult participants (74 nonstuttering and 4 persons with stuttering) completed one face-to-face structured interview regarding how much they would be willing to pay to alleviate severe stuttering in three interventions of varying impact. These data were compared with QALYs gained as calculated from time trade off (TTO) and standard gamble (SG) data. RESULTS: Mean (median) WTP bids ranged from US $16,875 (8000), for an intervention resulting in improvement from severe stuttering to mild stuttering, to US $41,844 (10,000) for an intervention resulting in a cure of severe stuttering. These data were consistent with mean changes in QALYs for the same stuttering interventions ranging from 2.19 (using SG) to 18.42 (using TTO). CONCLUSIONS: This study presents the first published WTP and QALY data for stuttering. Results were consistent with previous cost-of-illness data for stuttering. Both WTP and QALY measures were able to quantify the reduction in quality of life that occurs in stuttering, and both can be used to compare the gains that might be achieved by different interventions. It is widely believed that stuttering can cause reduced quality of life for some speakers; the introduction into this field of standardized metrics for measuring quality of life is a necessary step for transparently weighing the costs and consequences of stuttering interventions in economic analyses. EDUCATIONAL OBJECTIVES: The reader will be able to (a) describe the underlying theoretical foundations for willingness to pay and quality adjusted life years, (b) describe the application of willingness to pay and quality adjusted life years for use in economic analyses, (c) compare and contrast the value of willingness to pay and quality adjusted life years in measuring the impact of stuttering treatment on quality of life, (d) interpret quality adjusted life years, and (e) interpret willingness to pay data.

Assessment of respondent acceptability for preference measures in stuttering.

PURPOSE: To assess the feasibility of using one or more of four standard economic preference measures to assess health-related quality of life in stuttering, by assessing respondents' views of the acceptability of those measures. METHOD AND RESULTS: A graphic positioning scale approach was used with 80 adults to assess four variables previously defined as reflecting the construct of respondent acceptability (difficulty of decision making, clarity of text, reasonableness for decision making, and comfort in decision making) for four types of preference measurement approaches (rating scale, standard gamble, time trade-off, and willingness to pay). A multivariate repeated measures analysis of variance (p<.001) and follow-up univariate repeated measures analyses of variance (all p<.01) were all significant, indicating that respondents perceived differences among the preference measurement methods on all four acceptability variables. CONCLUSION: The rating scale was perceived as the easiest, clearest, most reasonable, and most comfortable tool, but it is not a measure of utility (an economic term for desirability or worth). If utility is the objective, such as for cost-utility analyses in stuttering, then the present results suggest the use of standard gamble (rather than time trade-off). These results also support the use of willingness to pay assessments for cost-benefit analyses in stuttering. These findings supplement results previously obtained for other chronic conditions. LEARNING OUTCOMES: The reader will be able to: (1) describe how four standard economic preference measures [rating scale (RS), time trade-off (TTO), standard gamble (SG), and willingness to pay (WTP)] can be used in economic analyses; (2) describe how RS, TTO, SG and WTP can be measured; and (3) describe how respondents perceive the use of RS, TTO, SG and WTP in measuring changes in stuttering.

Brain activity in adults who stutter: similarities across speaking tasks and correlations with stuttering frequency and speaking rate.

Many differences in brain activity have been reported between persons who stutter (PWS) and typically fluent controls during oral reading tasks. An earlier meta-analysis of imaging studies identified stutter-related regions, but recent studies report less agreement with those regions. A PET study on adult dextral PWS (n=18) and matched fluent controls (CONT, n=12) is reported that used both oral reading and monologue tasks. After correcting for speech rate differences between the groups the task-activation differences were surprisingly small. For both analyses only some regions previously considered stutter-related were more activated in the PWS group than in the CONT group, and these were also activated during eyes-closed rest (ECR). In the PWS group, stuttering frequency was correlated with cortico-striatal-thalamic circuit activity in both speaking tasks. The neuroimaging findings for the PWS group, relative to the CONT group, appear consistent with neuroanatomic abnormalities being increasingly reported among PWS.

Integrating functional measures with treatment: a tactic for enhancing personally significant change in the treatment of adults and adolescents who stutter.

PURPOSE: It is proposed that stuttering treatment, particularly for adults and adolescents who stutter, may benefit from more inventive and extensive use of functional measurement-measures that are also treatment agents. Such measures can be tailored to produce more personally significant and evidence-based treatment benefits. They may be especially useful when employed in conjunction with partial self-management and performance-contingent procedures. METHOD: Previous approaches to the definition of stuttering treatment goals and the measurement of stuttering treatment outcomes are critically reviewed. Suggestions for improvements are presented within the framework of an evidence-based and relatively standardized stuttering treatment. RESULTS AND CONCLUSION: Results from a review of existing literature and from 2 case studies show that 2 specific personally significant problems, saying one's name and addressing large audiences, were improved by implementing these strategies in treatment. Functional measures directly connected to treatment, and partially self-managed performance-contingent schedules, merit further research as methodologies that are suitable for conducting personally significant and evidence-based treatments with adults and adolescents who stutter.

Phonation interval modification and speech performance quality during fluency-inducing conditions by adults who stutter.

PURPOSE: To relate changes in four variables previously defined as characteristic of normally fluent speech to changes in phonatory behavior during oral reading by persons who stutter (PWS) and normally fluent controls under multiple fluency-inducing (FI) conditions. METHOD: Twelve PWS and 12 controls each completed 4 ABA experiments. During A phases, participants read normally. B phases were 4 different FI conditions: auditory masking, chorus reading, whispering, and rhythmic stimulation. Dependent variables were the durations of accelerometer-recorded phonated intervals; self-judged speech effort; and observer-judged stuttering frequency, speech rate, and speech naturalness. The method enabled a systematic replication of Ingham et al. (2009). RESULTS: All FI conditions resulted in decreased stuttering and decreases in the number of short phonated intervals, as compared with baseline conditions, but the only FI condition that satisfied all four characteristics of normally fluent speech was chorus reading. Increases in longer phonated intervals were associated with decreased stuttering but also with poorer naturalness and/or increased speech effort. Previous findings concerning the effects of FI conditions on speech naturalness and effort were replicated. CONCLUSIONS: Measuring all relevant characteristics of normally fluent speech, in the context of treatments that aim to reduce the occurrence of short-duration PIs, may aid the search for an explanation of the nature of stuttering and may also maximize treatment outcomes for adults who stutter. LEARNING OUTCOMES: The reader will be able to (1) understand the differential effects of four well established fluency-inducing conditions on the quality of fluency of adult PWS and controls, (2) learn how intervals of phonation are modified during these conditions and (3) how the duration of specific intervals of phonation may be identified for their potential application in stuttering treatment.

Systematic studies of modified vocalization: speech production changes during a variation of metronomic speech in persons who do and do not stutter.

UNLABELLED: The most common way to induce fluency using rhythm requires persons who stutter to speak one syllable or one word to each beat of a metronome, but stuttering can also be eliminated when the stimulus is of a particular duration (e.g., 1 second [s]). The present study examined stuttering frequency, speech production changes, and speech naturalness during rhythmic speech that alternated 1s of reading with 1s of silence. A repeated-measures design was used to compare data obtained during a control reading condition and during rhythmic reading in 10 persons who stutter (PWS) and 10 normally fluent controls. Ratings for speech naturalness were also gathered from naïve listeners. Results showed that mean vowel duration increased significantly, and the percentage of short phonated intervals decreased significantly, for both groups from the control to the experimental condition. Mean phonated interval length increased significantly for the fluent controls. Mean speech naturalness ratings during the experimental condition were approximately "7" on a 1-9 scale (1=highly natural; 9=highly unnatural), and these ratings were significantly correlated with vowel duration and phonated intervals for PWS. The findings indicate that PWS may be altering vocal fold vibration duration to obtain fluency during this rhythmic speech style, and that vocal fold vibration duration may have an impact on speech naturalness during rhythmic speech. Future investigations should examine speech production changes and speech naturalness during variations of this rhythmic condition. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) describe changes (from a control reading condition) in speech production variables when alternating between 1s of reading and 1s of silence, (2) describe which rhythmic conditions have been found to sound and feel the most natural, (3) describe methodological issues for studies about alterations in speech production variables during fluency-inducing conditions, and (4) describe which fluency-inducing conditions have been shown to involve a reduction in short phonated intervals.

Statistical, practical, clinical, and personal significance: definitions and applications in speech-language pathology.

PURPOSE: To discuss constructs and methods related to assessing the magnitude and the meaning of clinical outcomes, with a focus on applications in speech-language pathology. METHOD: Professionals in medicine, allied health, psychology, education, and many other fields have long been concerned with issues referred to variously as practical significance, clinical significance, social validity, patient satisfaction, treatment effectiveness, or the meaningfulness or importance of beyond-clinic or real-world treatment outcomes. Existing literature addressing these issues from multiple disciplines was reviewed and synthesized. CONCLUSIONS: Practical significance, an adjunct to statistical significance, refers to the magnitude of a change or a difference between groups. The appropriate existing term for the interpretation of treatment outcomes, or the attribution of meaning or value to treatment outcomes, is clinical significance. To further distinguish between important constructs, the authors suggest incorporating as definitive the existing notion that clinical significance may refer to measures selected or interpreted by professionals or with respect to groups of clients. The term personal significance is introduced to refer to goals, variables, measures, and changes that are of demonstrated value to individual clients.

Systematic studies of modified vocalization: effects of speech rate and instatement style during metronome stimulation.

PURPOSE: This study introduces a series of systematic investigations intended to clarify the parameters of the fluency-inducing conditions (FICs) in stuttering. METHOD: Participants included 11 adults, aged 20-63 years, with typical speech-production skills. A repeated measures design was used to examine the relationships between several speech production variables (vowel duration, voice onset time, fundamental frequency, intraoral pressure, pressure rise time, transglottal airflow, and phonated intervals) and speech rate and instatement style during metronome-entrained rhythmic speech. RESULTS: Measures of duration (vowel duration, voice onset time, and pressure rise time) differed across different metronome conditions. When speech rates were matched between the control condition and metronome condition, voice onset time was the only variable that changed. CONCLUSION: Results confirm that speech rate and instatement style can influence speech production variables during the production of fluency-inducing conditions. Future studies of normally fluent speech and of stuttered speech must control both features and should further explore the importance of voice onset time, which may be influenced by rate during metronome stimulation in a way that the other variables are not.

Measurement of speech effort during fluency-inducing conditions in adults who do and do not stutter.

PURPOSE: To investigate the effects of 4 fluency-inducing (FI) conditions on self-rated speech effort and other variables in adults who stutter and in normally fluent controls. METHOD: Twelve adults with persistent stuttering and 12 adults who had never stuttered each completed 4 ABA-format experiments. During A phases, participants read aloud normally. During each B phase, they read aloud in 1 of 4 FI conditions: auditory masking, chorus reading, whispering, and rhythmic speech. Dependent variables included self-judged speech effort and observer-judged stuttering frequency, speech rate, and speech naturalness. RESULTS: For the persons who stuttered, FI conditions reduced stuttering and speech effort, but only for chorus reading were these improvements obtained without diminishing speech naturalness or speaking rate. By contrast, speech effort increased during all FI conditions for adults who did not stutter. CONCLUSIONS: Self-rated speech effort differentiated the effects of 4 FI conditions on speech performance for adults who stuttered, with chorus reading best approximating normally fluent speech. More generally, self-ratings of speech effort appeared to constitute an independent, reliable, and validly interpretable dimension of fluency that may be useful in the measurement and treatment of stuttering.

Measurement of phonated intervals during four fluency-inducing conditions.

PURPOSE: Previous investigations of persons who stutter have demonstrated changes in vocalization variables during fluency-inducing conditions (FICs). A series of studies has also shown that a reduction in short intervals of phonation, those from 30 to 200 ms, is associated with decreased stuttering. The purpose of this study, therefore, was to test the hypothesis that the distribution of phonated intervals (PIs) should change during 4 of the most well-known FICs. METHOD: A repeated-measures design was used to explore the relationship between PIs and stuttering during 4 FICs: chorus reading, prolonged speech, singing, and rhythmic stimulation. Most conditions were conducted at 2 different speech rates. The distribution of PIs was measured during these conditions and was compared with PI distributions obtained during control conditions. RESULTS: Overall PI distributions were significantly different during all 4 FICs, as compared with control conditions. PIs in the range of 30-150 ms were reduced across all FICs, at all speech rates. CONCLUSION: These results provide further evidence of the importance of phonation variables to (a) our understanding of how FICs may operate and (b) the treatment of stuttering. These findings, along with previous studies that showed how purposefully reducing the number of short PIs resulted in the elimination of stuttering, suggest that treatment programs based on prolonged speech-or PIs, in particular-may benefit from emphasizing a reduction in the number of short PIs and a simultaneous increase in the number of longer PIs.

Identification of children's stuttered and nonstuttered speech by highly experienced judges: binary judgments and comparisons with disfluency-types definitions.

PURPOSE: The purposes of this study were (a) to determine whether highly experienced clinicians and researchers agreed with each other in judging the presence or absence of stuttering in the speech of children who stutter and (b) to determine how those binary stuttered/nonstuttered judgments related to categorizations of the same speech based on disfluency-types descriptions of stuttering. METHOD: Eleven highly experienced judges made binary judgments of the presence or absence of stuttering for 600 audiovisually recorded 5-s speech samples from twenty 2- to 8-year-old children who stuttered. These judgments were compared with each other and with disfluency-types judgments in multiple interval-by-interval assessments and by using multiple definitions of agreement. RESULTS: Interjudge agreement for the highly experienced judges in the binary stuttered/nonstuttered task varied from 39.0% to 89.1%, depending on methods and definitions used. Congruence between binary judgments and categorizations based on disfluency types also varied depending on methods and definitions, from 21.6% to 100%. CONCLUSIONS: Agreement among highly experienced judges, and congruence between their binary judgments of stuttering and categorizations based on disfluency types, were relatively high using some definitions and very low using others. These results suggest the use of measurement methods other than those based on disfluency types for quantifying or describing children's stuttering. They also suggest both the need for, and potential methods for, training to increase judges' accuracy and agreement in identifying children's stuttering.

Psychometric evaluation of condition-specific instruments used to assess health-related quality of life, attitudes, and related constructs in stuttering.

PURPOSE: This study assessed the psychometric properties of instruments used to measure constructs similar to stuttering-specific health-related quality of life. In the stuttering literature, most such instruments were originally intended to measure speakers' attitudes about, or reactions to, their stuttering. METHOD: Seventeen instruments were identified through a comprehensive literature search. Based on specific criteria from previous publications, 10 were selected for complete review and evaluated using 15 measurement standards related to conceptual model, reliability, validity, responsiveness, interpretability (norms), burden (respondent and administrative), depth, and versatility. RESULTS: None of the available instruments met more than 8 of the 15 measurement standards assessed. CONCLUSIONS: Available instruments do not satisfy psychometric criteria for use in individual or group-level decision making, either as measures of their originally intended constructs or as measures of health-related quality of life. Problems with the conceptual model, reliability, validity, and responsiveness of available instruments, as well as the lack of comprehensive normative data, combine to suggest the need for development and validation of a stuttering-specific health-related quality of life measure.

Patient-reported outcomes in stuttering treatment: conceptual framework.

Evaluation of: Yaruss JS, Quesal RW. Overall Assessment of the Speaker's Experience of Stuttering (OASES): documenting multiple outcomes in stuttering treatment. J. Fluency Disord. 31(2), 90-115 (2006) [1] . These authors presented the first complete instrument intended to measure the impact of stuttering in adults who stutter (Overall Assessment of the Speaker's Experience of Stuttering; [OASES]). OASES is a 100-item self-report metric with four sections: general information, reactions to stuttering, communication in daily situations and quality of life. Its conceptual framework includes historic views of the influence of emotional and cognitive variables on stuttering; the WHO's International Classification of Impairments, Disabilities and Handicaps (ICIDH); and the WHO's International Classification of Functioning, Disability and Health (ICF). However, both this conceptual framework and the psychometric data presented to support the OASES are problematic in ways that clinicians and researchers in areas well-beyond stuttering may find informative as they consider their own applications.

Stuttering treatment research 1970-2005: I. Systematic review incorporating trial quality assessment of behavioral, cognitive, and related approaches.

PURPOSE: To complete a systematic review, with trial quality assessment, of published research about behavioral, cognitive, and related treatments for developmental stuttering. Goals included the identification of treatment recommendations and research needs based on the available high-quality evidence about stuttering treatment for preschoolers, school-age children, adolescents, and adults. METHOD: Multiple readers reviewed 162 articles published between 1970 and 2005, using a written data extraction instrument developed as a synthesis of existing standards and recommendations. Articles were then assessed using 5 methodological criteria and 4 outcomes criteria, also developed from previously published recommendations. RESULTS: Analyses found 39 articles that met at least 4 of the 5 methodological criteria and were considered to have met a trial quality inclusion criterion for the purposes of this review. Analysis of those articles identified a range of stuttering treatments that met speech-related and/or social, emotional, or cognitive outcomes criteria. CONCLUSIONS: Review of studies that met the trial quality inclusion criterion established for this review suggested that response-contingent principles are the predominant feature of the most powerful treatment procedures for young children who stutter. The most powerful treatments for adults, with respect to both speech outcomes and social, emotional, or cognitive outcomes, appear to combine variants of prolonged speech, self-management, response contingencies, and other infrastructural variables. Other specific clinical recommendations for each age group are provided, as are suggestions for future research.

Stuttering treatment research 1970-2005: II. Systematic review incorporating trial quality assessment of pharmacological approaches.

PURPOSE: To complete a systematic review, incorporating trial quality assessment, of published research about pharmacological treatments for stuttering. Goals included the identification of treatment recommendations and research needs based on the available high-quality evidence. METHOD: Multiple readers reviewed 31 articles published between 1970 and 2005, using a written data extraction instrument developed as a synthesis of existing standards and recommendations. Articles were then assessed using 5 methodological criteria and 4 outcomes criteria, also developed from previously published recommendations. RESULTS: None of the 31 articles met more than 3 of the 5 methodological criteria (M = 1.74). Four articles provided data to support a claim of short-term improvement in social, emotional, or cognitive variables. One article provided data to show that stuttering frequency was reduced to less than 5%, and 4 additional articles provided data to show that stuttering may have been reduced by at least half. Among the articles that met the trial quality inclusion criterion for the second stage of this review, none provided uncomplicated positive reports. CONCLUSIONS: None of the pharmacological agents tested for stuttering have been shown in methodologically sound reports to improve stuttering frequency to below 5%, to reduce stuttering by at least half, or to improve relevant social, emotional, or cognitive variables. These findings raise questions about the logic supporting the continued use of current pharmacological agents for stuttering.

Comparing judgments of stuttering made by students, clinicians, and highly experienced judges.

PURPOSE: The purpose of this study was to compare judgments of stuttering made by students and clinicians with previously available judgments made by highly experienced judges in stuttering. METHOD: On two occasions, 41 university students and 31 speech-language pathologists judged the presence or absence of stuttering in each of 216 audiovisually recorded 5-s intervals of the speech of adults who stutter. Intrajudge and interjudge agreement were calculated, and comparisons were made to judgments previously made about the same recordings by 10 highly experienced judges of stuttering. RESULTS: Students and clinicians showed similar and relatively high levels of intrajudge and interjudge agreement, but both students and clinicians identified less than half as much stuttering as the highly experienced judges had identified. CONCLUSIONS: These results replicate previous findings of high agreement coexisting with low accuracy in students' judgments of stuttering, extending those findings to show that similar problems are evident in judgments made by practicing clinicians. Implications include the need for explicit stuttering judgment training programs for both students and practicing clinicians. EDUCATIONAL OBJECTIVES: After reading this article, the reader will be able to: (1) describe different methods for identifying stuttering and possible problems associated with each method; (2) describe two different methods for reporting interjudge reliability; (3) describe how the identification of stuttering differs for student, clinician, and highly experienced judges.

The Stuttering Treatment Research Evaluation and Assessment Tool (STREAT): evaluating treatment research as part of evidence-based practice.

PURPOSE: This article presents, and explains the issues behind, the Stuttering Treatment Research Evaluation and Assessment Tool (STREAT), an instrument created to assist clinicians, researchers, students, and other readers in the process of critically appraising reports of stuttering treatment research. METHOD: The STREAT was developed by combining and reorganizing previously published recommendations about the design and conduct of stuttering treatment research. CONCLUSIONS: If evidence-based practice is to be widely adopted as the basis for stuttering assessment and treatment, procedures must be developed and distributed that will allow students, clinicians, and other readers without specialized knowledge of research design to critically appraise treatment research reports. The STREAT is intended to be such an instrument: It represents the consensus of previous methodological recommendations; it is consistent with and complements existing recommendations in evidence-based medicine and in the broader science of treatment outcome evaluation; and it is formatted into a single instrument for ease of use.

Using preference-based measures to assess quality of life in stuttering.

PURPOSE: The purpose of this study was to determine whether standard pharmaco-economic preference methods can be used to assess perceived quality of life in stuttering. METHOD: Seventy-five nonstuttering adults completed a standardized face-to-face interview that included a rating scale, standard gamble, and time trade-off preference measures for 4 health states (your health and mild, moderate, and severe stuttering) in the context of 2 anchor states (perfect health and death). RESULTS: Results showed mean utility values between .443 for severe stuttering estimated using the rating scale technique and .982 for respondents' own current health estimated using a standard gamble technique. A two-way repeated measures analysis of variance and post hoc tests showed significant effects for method, health state, and the interaction. CONCLUSIONS: These results confirm that utility estimates can differentiate between stuttering severity levels and that utility scores for stuttering conform to the known properties of data obtained using these standard measurement techniques. These techniques, therefore, can and should be further investigated as potential contributors to complete measurement protocols for the study and treatment of stuttering.