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.     

The early history of behavior modification of stuttering: A view from the trenches

The attitudes of 644 employers toward stuttering were studied through the use of a questionnaire which required the respondents to indicate their strenght-of- agreement to seven attitudinal statements concerning stuttering. While rejecting the suggestion that stuttering interferes with job performance, the employers agreed that stuttering decreases employability and interferes with promotion possibilities. It was concluded that although stuttering may not typically interfere with job performance, it is a significant vocationally handicapping problem.     

Stuttering treatment control using P300 event-related potentials

Positron emission tomography studies during speech have indicated a failure to show the normal activation of auditory cortical areas in stuttering individuals. In the present study, P300 event-related potentials were used to investigate possible effects of behavioral treatment on the pattern of signal amplitude and latency between waves. In order to compare variations in P300 measurements, a control group paired by age and gender to the group of stutterers, was included in the study. Findings suggest that the group of stutterers presented a significant decrease in stuttering severity after the fluency treatment program. Regarding P300 measurements, stutterers and their controls presented results within normal limits in all testing situations and no significant statistical variations between pre and post treatment testing. When comparing individual results between the testing situations, stutterers presented a higher average decrease in wave latency for the right ear following treatment. The results are discussed in light of previous P300 event-related potentials and functional imaging studies with stuttering adults.Educational objectives: The reader will learn about and be able to describe the: (1) use of P300 event-related potentials in the study of stuttering; (2) differences between stuttering and non-stuttering adults; and (3) effects of behavioral fluency treatment on cerebral activity in stuttering speakers.     

Reprint of: stuttering treatment control using P300 event-related potentials

Positron emission tomography studies during speech have indicated a failure to show the normal activation of auditory cortical areas in stuttering individuals. In the present study, P300 event-related potentials were used to investigate possible effects of behavioral treatment on the pattern of signal amplitude and latency between waves. In order to compare variations in P300 measurements, a control group paired by age and gender to the group of stutterers, was included in the study. Findings suggest that the group of stutterers presented a significant decrease in stuttering severity after the fluency treatment program. Regarding P300 measurements, stutterers and their controls presented results within normal limits in all testing situations and no significant statistical variations between pre and post treatment testing. When comparing individual results between the testing situations, stutterers presented a higher average decrease in wave latency for the right ear following treatment. The results are discussed in light of previous P300 event-related potentials and functional imaging studies with stuttering adults.Educational objectives: The reader will learn about and be able to describe the: (1) use of P300 event-related potentials in the study of stuttering; (2) differences between stuttering and non-stuttering adults; and (3) effects of behavioral fluency treatment on cerebral activity in stuttering speakers.     

The effectiveness of SpeechEasy during situations of daily living

A multiple single-subject design was used to examine the effects of SpeechEasy on stuttering frequency in the laboratory and in longitudinal samples of speech produced in situations of daily living (SDL). Seven adults who stutter participated, all of whom had exhibited at least 30% reduction in stuttering frequency while using SpeechEasy during previous laboratory assessments. For each participant, speech samples recorded in the laboratory and SDL during device use were compared to samples obtained in those settings without the device. In SDL, stuttering frequencies were recorded weekly for 9-16 weeks during face-to-face and phone conversations. Participants also provided data regarding device tolerance and perceived benefits. Laboratory assessments were conducted at the beginning and the end of the longitudinal data collection in SDL. All seven participants exhibited reduced stuttering in self-formulated speech in the Device compared to No-device condition during the first laboratory assessment. In the second laboratory assessment, four participants exhibited less stuttering and three exhibited more stuttering with the device than without. In SDL, five of seven participants exhibited some instances of reduced stuttering when wearing the device and three of these exhibited relatively stable amounts of stuttering reduction during long-term use. Five participants reported positive changes in speaking-related attitudes and perceptions of stuttering. Further investigation into the short- and long-term effectiveness of SpeechEasy in SDL is warranted. Educational objectives: The reader will be able to summarize: (1) issues pertinent to evaluating treatment benefits of wearable fluency aids and evaluate (2) the effect of SpeechEasy on stuttering frequency and the perceived benefits of device use in situations of daily living, as assessed weekly over the course of 9-16 weeks of wear, for seven adults who stutter.     

Word-by-word analysis of observer agreement utilizing audio and audiovisual techniques

The purpose of this study was to compare audio and audiovisual techniques of analyzing stuttering behavior using a recently developed index of agreement (Young, 1975). Twenty speech pathologists identified moments of stuttering for ten adult stutterers using both audio and audiovisual methods. Although no statistically significant differences existed between the two conditions, the listeners had more difficulty identifying moments of stuttering during the audio condition when mild stutterers were used.     

Syntactic influences on stuttering in young child stutterers

This study examined the location and rate of stuttering in the spontaneous speech of nine young stutterers (4.0–6.6 yr) in relation to certain aspects of syntax. It was designed to answer the following questions: Is there more stuttering at clause onset (boundary) than at other points in the clause? Does the type of clause influence rate of stuttering? Is there more stuttering on complex than on simple sentences? The syntactic analysis defined 10 clause types (seven pertaining to complex sentences and three pertaining to simple sentences); clause boundaries (taking into account “filler” words occuring in such positions); and hierarchical constituent structure within sentences. Stuttering was found with significantly greater frequency at clause boundaries than at internal (nonboundary) positions of clauses. This was apparent for nine of the 10 clause types, the exception being complement clauses. The word “and” at the beginning of simple and complex sentences provoked a high rate of stuttering. The hierarchical structure within the clause did not influence the location of stuttering, and sentence complexity was not a factor in the rate of stuttering.     

A positron emission tomography study of short- and long-term treatment effects on functional brain activation in adults who stutter

Previous studies have shown that fluency-inducing techniques, such as choral speech, result in changes in neural activation as measured by functional neuroimaging. In the present study, positron emission tomography was used to investigate the effects of intensive behavioural treatment, followed by a 1-year maintenance program, on the pattern of cortical and subcortical activation in stuttering adults during silent and oral reading of single words. The results indicate changes in activation lateralisation, as well as a general reduction in overactivation, especially in the motor cortex, following treatment. The results are discussed in light of previous functional imaging studies with stuttering adults.

Educational objectives: The reader will learn about and be able to describe the: (1) use of functional neuroimaging PET in the study of stuttering; (2) differences in neural activation between stuttering and non-stuttering adults; and (3) effects of behavioural fluency treatment on cortical and subcortical activations in stuttering speakers.     

Developmental stuttering and the role of the supplementary motor cortex

Developmental stuttering is a frequent neurodevelopmental disorder with a complex neurobiological basis. Robust neural markers of stuttering include imbalanced activity of speech and motor related brain regions, and their impaired structural connectivity. The dynamic interaction of cortical regions is regulated by the cortico-basal ganglia-thalamo-cortical system with the supplementary motor area constituting a crucial cortical site. The SMA integrates information from different neural circuits, and manages information about motor programs such as self-initiated movements, motor sequences, and motor learning. Abnormal functioning of SMA is increasingly reported in stuttering, and has been recently indicated as an additional “neural marker” of DS: anatomical and functional data have documented abnormal structure and activity of the SMA, especially in motor and speech networks. Its connectivity is often impaired, especially when considering networks of the left hemisphere. Compatibly, recent data suggest that, in DS, SMA is part of a poorly synchronized neural network, thus resulting in a likely substrate for the appearance of DS symptoms. However, as evident when considering neural models of stuttering, the role of SMA has not been fully clarified. Herein, the available evidence is reviewed, which highlights the role of the SMA in DS as a neural “hub”, receiving and conveying altered information, thus “gating” the release of correct or abnormal motor plans.     

The differential effect of three auditory stimuli on the frequency of stuttering behaviors

In view of the frequent clinical use of external auditory stimuli in fluency building programs, the purpose of the present experiment was to compare the effects of rhythmic pacing, delayed auditory feedback, and high intensity masking noise on the frequency of stuttering by dysfluency type. Twelve normal hearing young adult stutterers completed an oral reading (approximately 250 syllables) and conversational speech task (3 min) while listening to the three auditory stimuli and during a control condition presented in random order. The results demonstrated that during oral reading all three auditory stimuli were associated with significant reductions in stuttering frequency. However, during conversational speech, only the metronome produced a significant reduction in total stuttering frequency. Individual dysfluency types were not differentially affected by the three auditory stimuli.     

Stuttering due to ischemic stroke

Acquired stuttering is a disorder of the fluency of speech. The mechanism underlying stuttering is unknown. It may occur after bilateral and unilateral cortical or subcortical brain damage. We report two cases who had stuttering resulting from left parietal infarction.     

A clinician survey of speech and non-speech characteristics of neurogenic stuttering

This study presents survey data on 58 Dutch-speaking patients with neurogenic stuttering following various neurological injuries. Stroke was the most prevalent cause of stuttering in our patients, followed by traumatic brain injury, neurodegenerative diseases, and other causes. Speech and non-speech characteristics were analyzed separately for these four etiology groups. Results suggested possible group differences, including site of lesion and influence of speech conditions on stuttering. Other characteristics, such as within-word localization of disfluencies and presence of secondary behaviors were comparable across the etiology groups. The implications of our results for the diagnosis of neurogenic stuttering will be discussed.

Educational objectives: After reading this article, the reader will be able to: (1) provide a concise overview of the main literature on neurogenic stuttering; (2) discuss the speech and non-speech characteristics of neurogenic stuttering; (3) provide an overview of current clinical practices for intervention with neurogenic stuttering patients and their perceived outcome.     

Comparing stuttering attitudes of preschool through 5th grade children and their parents in a predominately rural Appalachian sample

BackgroundTheories relating to young children’s social cognitive maturity and their prevailing social groups play important roles in the acquisition of attitudes. Previous research has shown that preschool and kindergarten children’s stuttering attitudes are characterized by stronger negative beliefs and self reactions than those of parents. By contrast, 12 year-old children’s stuttering attitudes have been shown to be similar to their parents’ attitudes. Other research indicates that parental stuttering attitudes are no different from attitudes of adults who are not parents.PurposeThe purpose of this study was to explore children’s stuttering attitudes of preschool through 5th grade children and to compare them to their parents’ attitudes.MethodChildren and parents from a rural Appalachian elementary school and child/parent pairs from other areas in the region responded to child and adult versions of the Public Opinion Survey of Human Attributes–Stuttering (POSHA–S/Child and POSHA–S). Seven grade levels were included: preschool, kindergarten, 1^st grade, 2^nd grade, 3^rd grade, 4^th grade, and 5^th grade.ResultsConfirming earlier research, younger children’s attitudes toward stuttering were considerably less positive than those of their parents. As children matured up to the fifth grade, however, their stuttering attitudes progressively were more positive. Parents’ stuttering attitudes were quite consistent across all seven grade levels.ConclusionsConsistent with theories of attitudinal development, between the ages of 4 and 11 years, children’s measured attitudes toward stuttering improved and gradually approximated the attitudes of their parents and the general public.     

Public attitudes toward—and identification of—cluttering and stuttering in Norway and Puerto Rico

PurposeThe study sought to compare public attitudes toward cluttering versus stuttering in Norway and Puerto Rico and to compare respondents’ identification of persons known with these fluency disorders.MethodAfter reading lay definitions of cluttering and stuttering, three samples of adults from Norway and three from Puerto Rico rated their attitudes toward cluttering and/or stuttering on modified versions of the POSHA-Cl (for cluttering) and POSHA-S (for stuttering). They also identified children and adults whom they knew who either or both manifested cluttering or stuttering.ResultsAttitudes toward cluttering were essentially unaffected by rating either cluttering only or combined cluttering and stuttering on the same questionnaire in both countries. The same was also true of stuttering. Attitudes were very similar toward both disorders although slightly less positive for cluttering. Norwegian attitudes toward both disorders were generally more positive than Puerto Rican attitudes. The average respondent identified slightly more than one fluency disorder, a higher percentage for stuttering than cluttering and higher for adults than children. Cluttering–stuttering was rarely identified.ConclusionGiven a lay definition, this study confirmed that adults from diverse cultures hold attitudes toward cluttering that are similar to—but somewhat less positive than—their attitudes toward stuttering. It also confirmed that adults can identify cluttering among people they know, although less commonly than stuttering. Design controls in this study assured that consideration of stuttering did not affect either the attitudes or identification results for cluttering.Educational objectives: The reader will be able to: (a) describe the effects—or lack thereof—of considerations of stuttering on attitudes toward cluttering; (b) describe differences in public identification of children and adults who either clutter or stutter; (c) describe differences between attitudes toward cluttering and stuttering in Norway and Puerto Rico.     

Listener perceptions of stuttering across two presentation modes: a quantitative and qualitative approach

The purpose of this study was to compare participants' quantitative and qualitative judgments of various forms and frequencies of stuttering, during either audiovisual or audio-only presentation modes. A total of 64 participants voluntarily agreed to participate in the study. Each participant was randomly assigned and exposed to only one of the four conditions of varying stuttering severity levels. The assigned speech sample was presented to the participant in either the audiovisual or audio-only mode. After watching or listening to the sample, participants completed a six-item Likert scale and were asked four open-ended questions. Comments made by listeners were developed into positive and negative comments as well as sorted into five theme clusters. The data analyses revealed a number of non-significant differences across mean Likert scale ratings for the six statements and for the number of positive and negative comments between the two presentation modes. However, the results provided partial support for the notion that as the frequency of stuttering increases, listeners tend to make increasingly more negative comments about the speaker. Additionally, there were no clear differences in comments across the five theme clusters between the two presentation modes. The findings suggest that the type of presentation mode does not appear to affect listeners' perceptions of stuttering to the same extent that stuttering severity does. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) describe how listeners perceive and react to various frequencies of stuttering; (2) explain how audiovisual versus audio-only samples impact listener perceptions of stuttering and (3) provide examples of the ways in which qualitative data can enhance the understanding of how listeners react to various levels of stuttering.     

Neurophysiologic markers of primary motor cortex for laryngeal muscles and premotor cortex in caudal opercular part of inferior frontal gyrus investigated in motor speech disorder: a navigated transcranial magnetic stimulation (TMS) study

Transcranial magnetic stimulation studies have so far reported the results of mapping the primary motor cortex (M1) for hand and tongue muscles in stuttering disorder. This study was designed to evaluate the feasibility of repetitive navigated transcranial magnetic stimulation (rTMS) for locating the M1 for laryngeal muscle and premotor cortical area in the caudal opercular part of inferior frontal gyrus, corresponding to Broca’s area in stuttering subjects by applying new methodology for mapping these motor speech areas. Sixteen stuttering and eleven control subjects underwent rTMS motor speech mapping using modified patterned rTMS. The subjects performed visual object naming task during rTMS applied to the (a) left M1 for laryngeal muscles for recording corticobulbar motor-evoked potentials (CoMEP) from cricothyroid muscle and (b) left premotor cortical area in the caudal opercular part of inferior frontal gyrus while recording long latency responses (LLR) from cricothyroid muscle. The latency of CoMEP in control subjects was 11.75 ± 2.07 ms and CoMEP amplitude was 294.47 ± 208.87 µV, and in stuttering subjects CoMEP latency was 12.13 ± 0.75 ms and 504.64 ± 487.93 µV CoMEP amplitude. The latency of LLR in control subjects was 52.8 ± 8.6 ms and 54.95 ± 4.86 in stuttering subjects. No significant differences were found in CoMEP latency, CoMEP amplitude, and LLR latency between stuttering and control-fluent speakers. These results indicate there are probably no differences in stuttering compared to controls in functional anatomy of the pathway used for transmission of information from premotor cortex to the M1 cortices for laryngeal muscle representation and from there via corticobulbar tract to laryngeal muscles.     

Stuttering onset after laryngectomy

Two cases of onset of stuttering subsequent to laryngectomy are reported. These patients demonstrate that the existence of a larynx is not necessary for the generation of stuttering. The findings support the hypothesis that neuromotor control of sound source (laryngeal or alaryngeal) plays a critical role in the generation of stuttering-type dysfluencies and, perhaps, even in the onset of stuttering. They also suggest that dramatic alteration in sound source has the potential for dramatically altering fluency.     

Voice initiation and termination time in stuttering and nonstuttering children

Voice initiation time (VIT) and voice termination time (VTT) was measured in seven stuttering and eight nonstuttering children ranging in age from 4 yr, 6 mo to 6 yr, 10 mo. The experimental task was the production of /a/ in response to a 1000-Hz pure tone. Voice initiation time was defined as the period of time elapsing between the onset of the auditory stimulus and the onset of the subject's response of /a/, as displayed on an oscilloscope. Voice termination time was defined as the latency between termination of the stimulus tone and the point at which the oscilloscopic signal decreased by 90%. No statistically significant differences were found between the two groups with respect to either VIT or VTT. In addition, no apparent relationships were present among VIT, VTT, or stuttering severity.