Speech kinematic variability in adults who stutter is influenced by treatment and speaking style.

AIM: We tested whether completion of the Comprehensive Stuttering Program (CSP) is associated with a reduction in speech kinematic variability relative to pre-treatment when adults who stutter (AWS) use a casual speaking manner or fluency skills. RATIONAL: Kinematic variability is higher in AWS suggesting a sensorimotor vulnerability; however, it is not clear whether high variability is a trait related to the underlying disorder or reflects the mutable state of stuttering. Speech restructuring intervention such as the CSP could support more consistent articulatory control and stable movement patterns. METHODOLOGY: Thirteen AWS were tested before and after completing the CSP while 11 adults who do not stutter (AWNS) completed a single session. Participants were instructed to use a casual manner of speaking in the first post-treatment session. In the second post-treatment condition, the AWS employed their fluency skills at a control speaking rate. An optical tracking system captured lower lip movements while participants spoke two English phrases and a complex nonword. Across-utterance kinematic variability was measured using the spatiotemporal index (STI) and within-utterance variability was measured with recurrence quantification analysis (RQA). RESULTS: There was a positive treatment outcome based on significant reductions in percentage syllables stuttered (%SS) during speaking and reading, decreases in stuttering severity and improved perceptions of stuttering and communication confidence. The STI of the AWS decreased significantly after treatment for both speaking styles. The RQA variables indicated that AWS used a less stereotyped and more flexible manner of speaking in the casual condition after treatment, but speech movement regularity increased when using fluency skills. CONCLUSIONS: The AWS showed a significant decrease in labial kinematic variability alongside a successful treatment outcome involving speech restructuring and cognitive behavioral techniques. These changes in across-utterance and within-utterance kinematic indices demonstrate that effective stuttering treatment can promote speech motor stability along with fluent speech.

Obtaining consensus on core components of stuttering intervention for adults: An e-Delphi Survey with key stakeholders.

BACKGROUND: Evidence-based practice involves the synthesis of multiple forms of evidence to inform clinical decision-making and treatment evaluation. Practice- and patient-based evidence are two forms of evidence that are under-represented in the stuttering literature. The collection of such knowledge is essential to support the design and delivery of effective stuttering interventions for adults. AIMS: To build stakeholder consensus on the core components of intervention for adults who stutter, and to establish a guiding framework for the design and development of evidence-based interventions for adults who stutter. METHODS & PROCEDURES: Adults who stutter and speech and language therapists (SLTs) with experience in providing stuttering intervention participated in the three-round e-Delphi Survey focused on: (1) identifying key stuttering intervention components, including principles, practices, and structural and contextual elements; and (2) obtaining group consensus on stuttering intervention components. Statements were categorized using the International Classification of Functioning, Disability and Health (ICF) model adapted to the study of stuttering. OUTCOMES & RESULTS: A total of 48 individuals agreed to participate: 48/48 (100%) completed the Round 1 questionnaire, 40/48 (83%) responded to Round 2 and 36/40 (90%) participated in Round 3. Following content analysis of Round 1, 101 statements were developed, and consensus was achieved on 89 statements perceived as representing the core components of stuttering intervention for adults. Categorization of these statements reflected the key stuttering intervention components relating to personal reactions to stuttering, limitations in life participation and environmental factors. CONCLUSIONS & IMPLICATIONS: Consensus on the core components of stuttering intervention was reached through engagement with key stakeholders. The evidence-based framework presented highlights the range of key intervention components a clinician should consider when designing interventions for adults who stutter. WHAT THIS PAPER ADDS: What is already known on the subject Evidence-based practice endorses the synthesis of multiple knowledge forms including research, practice and patient evidence to support clinical decision-making and treatment evaluation. The stuttering literature is characterized by an over-representation of efficacy evidence, with significantly less practice and patient evidence to guide clinical practice. What this paper adds to existing knowledge This study adds valuable practice- and patient-based evidence for effective stuttering intervention components for adults who stutter. These relate to personal reactions to stuttering, limitations in life participation and environmental factors. What are the potential or actual clinical implications of this work? This research presents a stakeholder-informed framework for stuttering intervention to guide SLTs working with adults who stutter in designing evidence-based interventions. The framework supports the adoption of a person-centred approach to intervention to ensure each client's unique needs, preferences, values and desired outcomes are explored and integrated into therapy.

A cross-cultural, long-term outcome evaluation of the ISTAR Comprehensive Stuttering Program across Dutch and Canadian adults who stutter.

UNLABELLED: There is a need to evaluate the effectiveness of stuttering treatment programs delivered in domestic and international contexts and to determine if treatment delivered internationally is culturally sensitive. Evaluation of the effectiveness of the ISTAR Comprehensive Stuttering Program (CSP) within and across client groups from the Netherlands and Canada revealed generally positive results. At 2 years post-treatment both groups were maintaining statistically significant reductions in stuttering frequency and improvements in attitudes, confidence, and perceptions as measured by the Revised Communication Attitude Inventory (S24), Perceptions of Stuttering Inventory (PSI), and the approach scale of the Self-Efficacy Scaling by Adult Stutterers (SESAS). Data pooled across the groups on these measures gave evidence of a global treatment effect with standardized effect sizes ranging from typical to larger than typical in the behavioural sciences. Only two differences between the groups emerged: differences in speech rate and perception of self. Given that these groups represent two distinct cultures, differences were discussed in terms of whether they could be due to cultural, methodological, or other variables. Overall, results suggest that, the CSP appears to be similarly effective in both cultures and thus, sufficiently sensitive to the culture of Dutch adults who stutter. EDUCATIONAL OBJECTIVES: The reader will be able to (a) describe a methodology that can be used in a clinical setting to evaluate the long-term effectiveness of stuttering treatment with adults, (b) describe some of the challenges in developing a model of clinically meaningful outcome, (c) explain the rationale for the need for cross-cultural investigations of treatment outcome, and (d) summarize speech and self-report results of the cross-cultural evaluation of an integrated stuttering treatment program.