Evidence-based treatment of stuttering: V. The art of clinical practice and the future of clinical research

This epilogue summarizes and expands on some of the many points raised in Parts I through IV, emphasizing that evidence-based practice is not in conflict with the "art" of clinical practice but may actually be synonymous. An evidence-based practice framework is also used to suggest some future directions for clinical research in stuttering. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to (1) describe the similarities between evidence-based practice and the art of clinical practice, (2) explain how evidence-based practice provides a structure for future stuttering research, and (3) evaluate the importance of an evidence-based approach to stuttering treatment.     

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.     

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 H₂¹⁵O 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

PurposeThe 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.MethodSeventy-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.ResultsMean (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).ConclusionsThis 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.     

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.     

"Roadblocks" revisited: neural change, stuttering treatment, and recovery from stuttering

In light of emerging findings concerning untreated recovery and neural plasticity, this paper re-examines the viability of an NIH conference recommendation [Cooper, J. A. (1990). Research directions in stuttering: Consensus and conflict. In Cooper, J. A. (Ed.), Research needs in stuttering: Roadblocks and future directions (pp. 98-100). Rockville, MD: American Speech-Language-Hearing Association.] that adults who have recovered from stuttering might inform our understanding of the nature and treatment of persistent stuttering. It is suggested that those who have recovered could constitute a behavioral, cognitive, and neurophysiologic benchmark for evaluating stuttering treatment for adolescents and adults, while helping to identify the limits of recovery from a persistent disorder. This possibility seems especially promising because of findings from recent studies investigating untreated recovery during childhood and adulthood, the emerging evidence concerning neural plasticity and reorganization, and reports of neural system changes during stuttering treatment. Potential obstacles to applying findings from unassisted recovery to treatment do exist, but the benefits of attempts to fully understand stuttering certainly outweigh the difficulties. EDUCATIONAL OBJECTIVES: After completing this activity, the learner will be able to: (1) describe two complexities involved in determining whether recovery from stuttering was assisted or unassisted; (2) discuss the implications for stuttering research of two neural plasticity research findings from areas other than stuttering; and (3) evaluate the possible implications for stuttering treatment of a coordinated research program that addresses behavioral, cognitive, and neurological characteristics of assisted and unassisted recovery from stuttering.     

Absolute sensitivity to white noise under auxiliary visual stimulation1

Absolute sensitivity to white noise was measured with the O in the dark, in constant illumination, and in the dark but with sound-synchronized flashes of light at three different intensities. A confidence rating procedure was used, and the results were analyzed in terms of the theory of signal detectability. There appeared to be no consistent effect of auxiliary visual stimulation on absolute auditory sensitivity for the four Os examined.     

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

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 1 s of reading with 1 s 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 1 s of reading and 1 s 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.