Treatment for Childhood Apraxia of Speech: Past, Present, and Future

PURPOSE

The purposes of this review article were to provide an introduction to and "bird's-eye" overview of the current evidence base for treatment of childhood apraxia of speech (CAS), identify some gaps and trends in this rapidly growing literature, and formulate some future research directions, in order to advance the evidence base and clinical practice for children with CAS.

METHOD

Following a brief introduction outlining important concepts, a narrative review of the CAS treatment literature is provided, and trends and future directions are identified based on this review. The review is organized around four fundamental treatment research questions: (a) "Does Treatment X work?", (b) "Does Treatment X work better than Treatment Y?", (c) "For whom does Treatment X work?", and (d) "What does 'work' mean, anyway?"

RESULTS

A wide range of CAS treatments with varying degrees of evidence for efficacy exists. Research is beginning to emerge that compares different treatments and seeks to determine optimal treatment parameters. Few studies to date have explored child-level predictors of treatment response, and the evidence base currently is limited in scope with respect to populations and outcomes studied.

CONCLUSIONS

A growing evidence base supports the efficacy of a number of treatments for CAS. However, many important gaps in the literature were identified that warrant redoubled and sustained research attention. Research is beginning to emerge that addresses treatment optimization, comparison, candidacy, and outcomes. Suggestions for future research are offered, and the concept of a hypothesized pathway was applied to CAS to illustrate how components of an intervention can effect change in a clinical goal and can help guide development and refinement of treatments for children with CAS.

A Comparison of Intervention Intensity and Service Delivery Models With School-Age Children With Speech Sound Disorders in a School Setting

Purpose This study examined intervention intensity and service delivery with school-age children with mild or mild-moderate speech sound disorders. The commonly used business-as-usual (BAU) service delivery model and a shorter, more frequent, individual model (experimental [EXP]) were compared. Method A between-subjects group design was selected. In BAU, 11 children received group sessions, 2 times per week, 30 min per session for 6 weeks. In EXP, 11 children received individual session, 3 times per week, 5 min per session for 6 weeks. Group differences on measures of dose (i.e., therapeutic input and production trials) and cumulative treatment intensity were examined. The extent to which children, across both conditions, demonstrated gains in speech sound accuracy and the extent to which gains differed between BAU and EXP were examined. Results There was a significant group difference on dose. Children in BAU received more therapeutic input and production trials than children in EXP. Cumulative treatment intensity was not statistically different between groups when dose was calculated as therapeutic input or production trials. Results from both conditions indicated statistically significant differences on measures of speech sound accuracy with large effect sizes. No group differences on gains were noted. Conclusions Dose calculated as therapeutic input and production trials plays an important role in understanding the impact of cumulative intervention intensity. Children with mild or mild-moderate speech sound disorders may benefit more from a shorter, frequent, individual service delivery model than a BAU model.

A meta-analysis on the effectiveness of intervention in children with primary speech and language delays/disorders: Focusing on China and the United States

The purpose of this meta-analysis was to investigate the immediate and long-term effects of intervention for children with primary speech and language delays/disorders and to explore whether some characteristics of interventions, specifics of the study and research participants moderate the magnitude of the effectiveness of interventions. Using the random effect model, we pooled the effect size and conducted a publication bias evaluation, a moderating effect analysis in CMA 2.0. Results of a random effects model analysis demonstrated a moderate immediate effect (g = 0.70), whereas the long-term efficacy was small (g = 0.23). Additionally, type of measure, language of intervention, parental involvement, intervention content and study quality, as well as the duration of intervention, significantly moderated the effect size of intervention effectiveness.

Contributions to Gain in Speech Sound Production Accuracy for Children With Speech Sound Disorders: Exploring Child and Therapy Factors

Purpose The purpose of this study was to explore the extent to which child- and therapy-level factors contribute to gains in speech sound production accuracy for children with speech sound disorders in receipt of school-based services. Method Data were obtained from 126 kindergarten and first- and second-grade children currently in receipt of speech therapy services in their public school setting. Pretest and posttest measures of spontaneous speech production and language ability were collected at the beginning and end of one academic year. Using a spontaneous speech sample, percentage of consonants correct (PCC) was calculated for each child; a gain score was computed by subtracting the pretest PCC score from the posttest PCC score. The children's speech-language pathologist completed weekly therapy logs during business-as-usual therapy, indicating the frequency, duration, and group composition of services throughout the school year. Results Results supported that gain in PCC from pretest to posttest was predicted by several child- and therapy-level variables. Children's initial speech sound severity was negatively related to gains in PCC. Our results also supported that the total number of therapy sessions received in a year was positively predictive of PCC gain. Interestingly, the number of individual therapy sessions was negatively associated with PCC gain. Conclusion Several malleable therapy factors contribute to gains in speech sound accuracy for children with speech sound disorders. Speech-language pathologists should consider how these factors may be manipulated to best tailor treatment to the individual needs of the children on their caseloads.

Tutorial: Speech Motor Chaining Treatment for School-Age Children With Speech Sound Disorders

Purpose Operationalized treatments for school-age children with speech sound disorders may result in more replicable and evidence-based interventions. This tutorial describes Speech Motor Chaining (SMC) procedures, which are designed to build complex speech around core movements by incorporating several principles of motor learning. The procedures systematically manipulate factors such as feedback type and frequency, practice variability, and stimulus complexity based on the child's performance. Method The rationale and procedures for SMC are described. Examples are presented of how to design stimuli, deliver feedback, and adapt the approach. Free resources are provided to guide clinicians through implementation of the procedure. Data on fidelity of implementation and dose per session are presented. Clinical and research evidence is provided to illustrate likely outcomes with the procedure. Results SMC is a method that can result in successful acquisition of target speech patterns and generalization to untrained words. Most clinicians can implement the procedure with over 90% fidelity, and most children can achieve over 200 trials per session. Conclusion Clinicians and researchers can use or adapt the operationally defined SMC procedures to incorporate several principles of motor learning into treatment for school-age children with speech sound disorders. Supplemental Material https://osf.io/5jmf9/.

Service delivery and intervention intensity for phonology-based speech sound disorders

BACKGROUND

When planning evidence-based intervention services for children with phonology-based speech sound disorders (SSD), speech and language therapists (SLTs) need to integrate research evidence regarding service delivery and intervention intensity within their clinical practice. However, relatively little is known about the optimal intensity of phonological interventions and whether SLTs' services align with the research evidence.

AIMS

The aims are twofold. First, to review external evidence (i.e., empirical research evidence external to day-to-day clinical practice) regarding service delivery and intervention intensity for phonological interventions. Second, to investigate SLTs' clinical practice with children with phonology-based SSD in Australia, focusing on service delivery and intensity. By considering these complementary sources of evidence, SLTs and researchers will be better placed to understand the state of the external evidence regarding the delivery of phonological interventions and appreciate the challenges facing SLTs in providing evidence-based services.

METHODS & PROCEDURES

Two studies are presented. The first is a review of phonological intervention research published between 1979 and 2016. Details regarding service delivery and intervention intensity were extracted from the 199 papers that met inclusion criteria identified through a systematic search. The second study was an online survey of 288 SLTs working in Australia, focused on the service delivery and intensity of intervention provided in clinical practice.

MAIN CONTRIBUTIONS

There is a gap between the external evidence regarding service delivery and intervention intensity and the internal evidence from clinical practice. Most published intervention research has reported to provide intervention two to three times per week in individual sessions delivered by an SLT in a university clinic, in sessions lasting 30-60 min comprising 100 production trials. SLTs reported providing services at intensities below that found in the literature. Further, they reported workplace, client and clinician factors that influenced the intensity of intervention they were able to provide to children with phonology-based SSD.

CONCLUSIONS & IMPLICATIONS

Insufficient detail in the reporting of intervention intensity within published research coupled with service delivery constraints may affect the implementation of empirical evidence into everyday clinical practice. Research investigating innovative solutions to service delivery challenges is needed to provide SLTs with evidence that is relevant and feasible for clinical practice.