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Biomedical subjects

Mark Onslow

Publications and source records attributed to Mark Onslow.

At least 19 recordsLinked to original sources
PubMed2006

An investigation of language and phonological development and the responsiveness of preschool age children to the Lidcombe Program.

UNLABELLED: Knowledge of variables that predict treatment time is of benefit in deciding when to start treatment for early stuttering. To date, the only variable clearly related to treatment time with the Lidcombe Program is pre-treatment stuttering frequency. Previous studies have shown that children whose stuttering is more severe take longer to complete Stage 1 of the program. However, studies to date have not investigated phonology and language as predictors of treatment time. In the context of a Phase II clinical trial, the present prospective study showed that phonological development does not predict treatment time but that, together, stuttering severity, MLU and CELF Receptive Score predict 35-45% of the variance for time taken to complete Stage 1. LEARNING OUTCOMES: The reader should be able to (1) understand guidelines developed for the timing of intervention with the Lidcombe Program based on previous retrospective studies, (2) determine whether pre-treatment language and phonological development play a role in treatment-led recovery with the Lidcombe Program and (3) understand recent empirical evidence on time taken by preschool children to complete Stage 1 of the Lidcombe Program.

Behavior Therapy↗
PubMed2006

Altered auditory feedback and the treatment of stuttering: a review.

UNLABELLED: Several authors have suggested that devices delivering altered auditory feedback (AAF) may be a viable treatment for adults and children who stutter. This paper reviews published, peer reviewed journal papers from the past 10 years that investigate the effect of AAF during different speaking conditions, tasks and situations. A review of that literature indicates that considerable experimental evidence and limited Phase 1 treatment outcome evidence has been accumulated about the effect of AAF on the speech of people who stutter. However, critical knowledge about the effect of AAF during conversational speech and in everyday speaking situations is missing. Knowledge about how to determine the correct levels of AAF for individuals, and the characteristics of those likely to benefit from AAF, also needs to be established. At present there is no reason to accept a recent suggestion that AAF devices would be a defensible clinical option for children. In general device development and availability has occurred at a faster pace than clinical trials research. EDUCATIONAL OBJECTIVES: After reading this paper readers should be able to: (1) describe what altered auditory feedback is and common ways the speech signal is altered in stuttering; (2) describe the effects of AAF on the speech of adults who stutter; (3) provide a critical analysis of the literature in the area of AAF and stuttering.

Acoustic Stimulation↗
PubMed2006

A phase II clinical trial of self-imposed time-out treatment for stuttering in adults and adolescents.

PURPOSE: This study reports the development and clinical trial of a new treatment program for persistent developmental stuttering in adolescents and adults. The treatment is based on the operant procedure of self-imposed time-out. This involves the person stopping speaking for a short period after each stutter. METHOD: Twenty-two participants completed Stage 1 (Instatement and Generalisation) of the program and 18 completed Stage 2 (Maintenance) of the program. Stuttering outcome was measured from independent audio and video recordings made outside and inside the clinic, before and after treatment. Speech naturalness was measured at the end of Stage 1. Secondary analyses were conducted to investigate whether responsiveness to the program was related to stuttering severity or age. Participants completed an extensive self-report inventory at the end of treatment. RESULTS: There was a range of responsiveness to the treatment, with more than half the participants reducing their stuttering by more than 50%. Participants with more severe types of stuttering appeared to respond better but no other predictors of responsiveness were identified. Speech sounded reasonably natural after treatment. Participants' perceptions of the treatment were for the most part positive with the majority reporting that the treatment was easier to use and more effective than treatment based on prolonged-speech. CONCLUSIONS: The self-imposed time-out treatment program reported here is clearly effective for a significant number of adolescents and adults who stutter. Given that it does not require speech restructuring and the constant attention to speech that this involves, this could be a treatment of choice for those who are likely to respond. Consequently, further research is needed to determine which clients seeking behavioural treatment for their stuttering will benefit most from this program. Further research is also needed to determine the extent to which the effectiveness of time-out is increased when combined with other behavioural treatments.

Adolescent↗
PubMed2006

Guidelines for statistical analysis of percentage of syllables stuttered data.

PURPOSE: The purpose of this study was to develop guidelines for the statistical analysis of percentage of syllables stuttered (%SS) data in stuttering research. METHOD: Data on %SS from various independent sources were used to develop a statistical model to describe this type of data. On the basis of this model, %SS data were simulated with varying means, standard deviations, and sample sizes. Four methods for analyzing %SS were compared. RESULTS: Results suggested that %SS data can be adequately modeled with a gamma distribution. Simulations based on a gamma distribution showed that all 4 analysis techniques performed favorably with respect to Type I error except for F. E. Satterthwaite's (1946) t test, which had increased Type I error on two occasions. Power was generally lower for the Wilcoxon-Mann-Whitney test compared with the other methods. Analysis of variance (ANOVA) performed on square-root-transformed data performed adequately under all scenarios, but ANOVA performed on nontransformed data and Satterthwaite's t test performed poorly when sample sizes were small or when sample sizes and variances of the groups were markedly different. CONCLUSIONS: Standard techniques such as t test and ANOVA are appropriate for most analysis scenarios with %SS data. Two occasions when this is not the case are when sample size is small, with fewer than 20 in each group, or when sample sizes and variances of the groups are markedly different. Under these circumstances, analyses should be based on standard methods, with a suitable transformation performed prior to analysis.

Analysis of Variance↗
PubMed2005

Randomised controlled trial of the Lidcombe programme of early stuttering intervention.

OBJECTIVES: To evaluate the efficacy of the Lidcombe programme of early stuttering intervention by comparison to a control group. DESIGN: A pragmatic, open plan, parallel group, randomised controlled trial with blinded outcome assessment. SETTING: Two public speech clinics in New Zealand. PARTICIPANTS: Stuttering preschool children who presented to the speech clinics for treatment. Inclusion criteria were age 3-6 years and frequency of stuttering of at least 2% syllables stuttered. Exclusion criteria were onset of stuttering during the six months before recruitment and treatment for stuttering during the previous 12 months. 54 participants were randomised: 29 to the Lidcombe programme arm and 25 to the control arm. 12 of the participants were girls. INTERVENTION: Lidcombe programme of early stuttering intervention. MAIN OUTCOME MEASURES: Frequency of stuttering was measured as the proportion of syllables stuttered, from audiotaped recordings of participants' conversational speech outside the clinic. Parents in both arms of the trial collected speech samples in three different speaking situations before randomisation and at three, six, and nine months after randomisation. RESULTS: Analysis showed a highly significant difference (P = 0.003) at nine months after randomisation. The mean proportion of syllables stuttered at nine months after randomisation was 1.5% (SD 1.4) for the treatment arm and 3.9% (SD 3.5) for the control arm, giving an effect size of 2.3% of syllables stuttered (95% confidence interval 0.8 to 3.9). This effect size was more than double the minimum clinically worthwhile difference specified in the trial protocol. CONCLUSIONS: The results provide evidence from a randomised controlled trial to support early intervention for stuttering. The Lidcombe programme is an efficacious treatment for stuttering in children of preschool age.

Child↗
PubMed2004

Social anxiety in stuttering: measuring negative social expectancies.

UNLABELLED: Much research has suggested that those who stutter are likely to be anxious. However, to date, little research on this topic has addressed the role of expectancies of harm in anxiety, which is a central construct of anxiety in modern clinical psychology. There are good reasons to believe that the anxiety of those who stutter is related to expectancies of social harm. Therefore, in the present study, 34 stuttering and 34 control participants completed the Fear of Negative Evaluation (FNE) Scale and the Endler Multidimensional Anxiety Scales-Trait (EMAS-T). The FNE data showed a significant difference between the stuttering and control participants, with a large effect size. Results suggested that, as a group, a clinical population of people who stutter has anxiety that is restricted to the social domain. For the EMAS-T, significant differences between groups were obtained for the two subtests that refer specifically to people and social interactions in which social evaluation might occur (Social Evaluation and New/Strange Situations) but not for the subtests that contained no specific reference to people and social interactions (Physical Danger and Daily Routines). These results were taken to suggest that those who stutter differ from control subjects in their expectation of negative social evaluation, and that the effect sizes are clinically significant. The findings also suggest that the FNE and the EMAS-T are appropriate psychological tests of anxiety to use with stuttering clients in clinical settings. The clinical and research implications of these findings are discussed, in terms of whether social anxiety mediates stuttering or is a simple by-product of stuttering. Possible laboratory explorations of this issue are suggested, and potential Cognitive Behavior Therapy packages for stuttering clients who might need them are discussed. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) explain why expectancy of social threat or harm may be associated with stuttering; (2) name and describe two psychological tests that are suitable for assessment of the social threat or harm that may be associated with stuttering; and (3) explain how findings for the EMAS-T test in the present results suggest that expectancy of social threat or harm, but not other kinds of negative expectancy, are associated with stuttering.

Adult↗
PubMed2004

Telehealth adaptation of the Lidcombe Program of Early Stuttering Intervention: five case studies.

This article describes and reports data-based outcomes of a low-tech telehealth adaptation of the Lidcombe Program of Early Stuttering Intervention. Participants were 5 children with early stuttering, ranging in age from 3;5 (years;months) to 5;7, and their families. All children met the speech criteria for completion of Stage 1 of the Lidcombe Program. Data suggested that the treatment method may be viable and that favorable outcomes may be achievable. Mean posttreatment stuttering rates in everyday speaking situations were available 12 months posttreatment for 4 children. Two children scored a mean percent syllables stuttered of less than 1.0 at that time, and 2 children scored a mean of below 2.0. As occurs often in standard delivery of the Lidcombe Progam, 1 child relapsed after Stage 1, apparently because of parental noncompliance, but this relapse was managed successfully. Follow up data were unavailable for 1 child. For 4 of the 5 cases, the number of consultations required exceeded established benchmarks for standard Lidcombe Program delivery, suggesting that telephone-based telehealth may be a less efficient version of the treatment. The implications of these preliminary data are discussed.

Child, Preschool↗
PubMed2004

Self-rating of stuttering severity as a clinical tool.

Scaling is a convenient and equipment-free means for speech-language pathologists (SLPs) and clients to evaluate stuttering severity in everyday situations. This study investigated the extent to which the severity ratings of 10 adult stuttering speakers, made immediately after speaking and again from recordings 6 months later, agreed with ratings made by an SLP. For 9 of the 10 speakers, there was good agreement between their initial ratings and those of the SLP. For 8 of the 10 speakers, there was also good agreement between their initial ratings and those made from recordings 6 months later, indicating that the severity ratings made at the time of speaking were reliable. These findings support the use of the 9-point scale as a clinical measurement procedure.

Adult↗
PubMed2004

Measurement of stuttering in adults: comparison of stuttering-rate and severity-scaling methods.

This study investigated the comparative reliability of 2 stuttering measurement tools when used by experienced judges: percentage of syllables stuttered (%SS) and a 9-point severity scale (SEV). The study also investigated the degree to which scores on 1 tool predict scores on the other and the distributions of stuttering when measured by these tools. Twelve experienced judges watched 3-min videotapes of 90 stuttering and 10 nonstuttering participants. Half the judges rated %SS, and half made severity ratings. Results showed very high intrajudge and interjudge agreement for both measures. There was a strong linear correlation between %SS scores and SEV scores. Based on this finding, it seems that the 2 measures can be regarded as largely interchangeable. The exception to this, however, was in cases where there was either a small number of significant fixed postures (blocks and prolongations) or a large number of innocuous repeated movements (repetitions) in the speech sample. In such cases, it appears that %SS and SEV scores combined would be needed to provide a valid measure of stuttering. SEV scores were more normally distributed than %SS scores, which were clearly skewed. The advantages and limitations of the SEV scale are discussed.

Adolescent↗
PubMed2003

Evidence-based treatment of stuttering: IV. Empowerment through evidence-based treatment practices.

UNLABELLED: Assertion-based treatments for stuttering have historically been more popular than evidence-based treatments. In this paper it is argued that the use of evidence-based treatments for stuttering is professionally empowering for clinicians, but that the use of assertion-based treatments is a circular process that inhibits professional development. The arguments in favor of evidence-based treatment are elaborated under headings of "professional investment," "professional development and diversity," and "optimizing treatment efficacy." EDUCATIONAL OBJECTIVES: The reader will understand and be able (1) to describe the distinction between assertion-based and evidence-based treatment practices (2) to present a series of arguments that evidence-based treatment practices are professionally empowering.

Evidence-Based Medicine↗
PubMed2003

Is listener comfort a viable construct in stuttering research?

This article reports the development of a tool for measuring how comfortable a person feels when communicating with someone who has undergone treatment for stuttering. The person rates the speaker on a 9-point Listener Comfort Scale (9 = extremely comfortable, 1 = extremely uncomfortable). In a preliminary investigation of the reliability and validity of the scale, 15 unsophisticated listeners rated video recordings of 10 adults before and after a prolonged-speech treatment for stuttering and of 10 matched controls. The results were compared with those of another 15 listeners who rated the same recordings with the widely used 9-point Speech Naturalness Scale (R. R. Martin, S. K. Haroldson, & K. A. Triden, 1984). Results showed that reliability of the Speech Naturalness Scale was superior to the Listener Comfort Scale, although users of both scales were able to distinguish between pretreatment speech, posttreatment speech, and the speech of controls. The results suggest that the Listener Comfort Scale captures information that is somewhat different than the information captured by the Speech Naturalness Scale. The authors concluded that the concept of listener comfort is a potentially useful additional way of investigating the social validity of behavioral treatments for stuttering.

Adolescent↗
PubMed2003

Generalizability Theory I: Assessing reliability of observational data in the communication sciences.

Perceptual rating scales can be valid, reliable, and convenient tools for evaluating speech outcomes in research and clinical practice. However, they depend on the perceptions of observers. Too few raters may compromise accuracy, whereas too many would be inefficient. There is therefore a need to determine the minimum number of raters required for a reliable result. In this context, the ideas of Generalizability Theory have become increasingly popular in the behavioral sciences; suggestions have been made for their application to the assessment of speech-language disorders. Here we review the concepts involved, which are applied in a companion article dealing with speech naturalness data obtained from clients who recently completed treatment for their stuttering. We pay particular attention to the statistical requirements of the theory, including some cautions about possible inappropriate use of these techniques. We also offer a new interpretation of the results of the analysis that aims to be more meaningful to most speech-language pathologists.

Analysis of Variance↗
PubMed2003

Generalizability Theory II: Application to perceptual scaling of speech naturalness in adults who stutter.

Generalizability theory has been recommended as the most comprehensive method for assessing the reliability of observational data. It provides a framework for calculating the various sources of measurement error and allows further design of measurements for a particular purpose. This paper gives a practical illustration of how this method may be used in the analysis of observational data. We use the ratings of 15 unsophisticated raters using the 9-point speech naturalness scale of R. R. Martin, S. K. Haroldson, and K. A. Triden (1984) to evaluate the speech of adults before and after treatment for stuttering. We calculate various sources of measurement error and use these to estimate the minimum number of raters and ratings per rater for a reliable result. For posttreatment data, the average of three independent raters, and for pretreatment data, the average of five independent raters should give a result within one scale point of the hypothetical true score for the speaker in at least 80% of samples. The example illustrates the advantages of using this method of analysis.

Adult↗
PubMed2003

The Camperdown Program: outcomes of a new prolonged-speech treatment model.

Considerable research has been directed at the outcomes of prolonged-speech (PS) treatment for the control of chronic stuttering, but little research to date has focused on the PS treatment process. This report examines a Stage 2 clinical trial of a reconceptualized PS treatment model known as the Camperdown Program. This program requires fewer clinician hours than traditional programs and has no formal transfer phase. Additionally, it incorporates the following treatment process innovations, which replace treatment process components that are intuitively and empirically problematic: (a) PS is taught without incorporating target behaviors in clinician instruction, (b) participants learn to control stuttering without programmed instruction, and (c) the treatment process does not involve clinician identification of stuttering moments. Thirty participants were initially enrolled in the trial. Final outcome data are presented for the 16 participants who completed all trial requirements, including 12 months posttreatment data collection. These 16 participants showed minimal or no stuttering in everyday speaking situations for up to 12 months after entering the maintenance program, with speech rates in the normal range. Speech naturalness and social validation data were also favorable. Although self-report data generally confirmed the speech data, the results were not as positive. The present outcomes were achieved in a mean of 20 hours of clinic attendance per participant, which is much fewer than the hours required by treatment programs reported recently that run intensively over 2-3 weeks. The promise of this Stage 2 clinical trial has led the authors to initiate a Stage 3 randomized controlled trial of the Camperdown Program.

Adolescent↗
PubMed2003

The Lidcombe Behavioral Data Language of stuttering.

The Lidcombe Behavioral Data Language (LBDL; K. Bryant & A. Packman, 1999; A. Packman & M. Onslow, 1998; A. Packman, M. Onslow, & K. Bryant, 2000) is a recently developed taxonomy of stuttering. It fills a void in stuttering research because most current descriptive systems are taxonomies of disfluencies, not stuttering alone, and are not behaviorally based. This study is an investigation of intrajudge and interjudge agreement for the LBDL. Ten experienced speech-language pathologists and 10 undergraduate students received brief instruction in the LBDL and then applied it to 15 intervals of stuttered speech on 2 occasions. The speakers were children and adults. Intrajudge agreement was high for both groups but only experienced judges achieved satisfactory interjudge agreement. Results suggest that some stuttering behaviors may be easier to categorize than others. Possible applications of the LBDL to research and clinical practice in stuttering are discussed.

Adolescent↗
PubMed2002

An experimental investigation of the impact of the Lidcombe Program on early stuttering.

Preliminary Phase I and II trials for the Lidcombe Program of early stuttering intervention have found favorable outcomes and that the treatment is safe. Although speech-language pathologists (SLPs) often need to intervene with pre-schoolers' early stuttering, many of these children will recover at some time in the future without such intervention. Consequently, they need to know whether the Lidcombe Program's effect on stuttering is greater than that of natural recovery. Participants were 23 pre-school children who were randomly assigned to either a control group or a treatment group that received the Lidcombe Program for 12 weeks. A repeated measures ANOVA showed no main effect on stuttering for the group (control/treatment), a significant main effect for the measurement occasion (at the start and at the end of the treatment period), and a significant interaction between group and measurement occasion. Stuttering in the treatment group reduced twice as much as in the control group. These results are interpreted to mean that the introduction of the Lidcombe Program has a positive impact on stuttering rate, which exceeds that attributable to natural recovery.

Child↗