Treatment for phonologically disordered children with variable substitution patterns

A single case experimental design study using an operationalised version of the Kaufman Speech to Language Protocol for children with childhood apraxia of speech

PURPOSE

A Phase I study was conducted to examine the treatment effectiveness of the Kaufman Speech to Language Protocol using a research-operationalised protocol. It was hypothesised that articulatory accuracy would improve as a result of the treatment and that these improvements would be maintained after treatment was discontinued.

METHOD

A single case experimental design was used to evaluate the effectiveness of the Kaufman Speech to Language Protocol. Four children with a confirmed childhood apraxia of speech diagnosis were included in this study. Each child received 12 individual 1 hr treatment sessions that each consisted of an approximation setting phase and a practice phase. Probe data was collected during treatment and at post-treatment time points to measure treatment effectiveness and to measure changes in the untreated words. Untreated (control) sounds were included to test whether recorded improvements in articulatory accuracy could be attributed to the Kaufman Speech to Language Protocol.

RESULT

Two of the four children demonstrated a response to the intervention and maintenance of these changes, while the two remaining children demonstrated some generalisation in the absence of improved target (treatment) words. No specific child factors were clearly associated with positive treatment outcomes.

CONCLUSION

This study replicated the findings of an earlier pilot study and found that the operationalised protocol for the Kaufman Speech to Language Protocol is effective in improving articulatory accuracy for some children with childhood apraxia of speech. Additional replication with a further refined treatment protocol and a larger sample size is needed to support a recommendation of clinical use of the Kaufman Speech to Language Protocol.

Predictors of Speech Severity and Inconsistency Over Time in Children With Token-to-Token Inconsistency

PURPOSE

The aim of this study was to describe and explain changes in severity of speech sound disorder (SSD) and token-to-token inconsistency in children with high levels of inconsistency.

METHOD

Thirty-nine children (aged 4;6-7;11 [years;months]) with SSDs and high levels of token-to-token inconsistency were assessed every 6 months for 2 years (i.e., five assessment points). Growth modeling was used to assess relations among therapy support, receptive vocabulary, severity, and inconsistency over time.

RESULTS

Children with the most severe SSDs and highest levels of token-to-token inconsistency showed the smallest improvements in speech accuracy over time. Therapy support did not predict changes in speech accuracy or token-to-token inconsistency over time. Receptive vocabulary (measured at the outset of the study) was also a significant predictor of speech accuracy and inconsistency.

CONCLUSIONS

These findings suggest that an immediate start to intervention (rather than a wait-and-see approach) is recommended for children with inconsistent speech error patterns. The results also highlight the value of developing vocabulary knowledge in addition to improving speech accuracy for some children with inconsistent speech production.

Intra-word consistency and accuracy in Finnish children aged 3-6 years

This study examined intra-word consistency and accuracy in typically developing Finnish children and their relation to children's vocabulary size and phonological skills. A total of 80 typically developing Finnish children aged 3;0 to 6;11 were asked to name 20 words three separate times during a single assessment session. Responses were classified into four categories: 1) consistently correct productions, 2) consistently incorrect productions, 3) variable productions with hits (variable productions including at least one matched adult target), and 4) variable productions with no hits. The results revealed that 5- and 6-year-old children produced significantly more often consistently correct responses than younger children. However, even for the 3- and 4-year old children the most frequent response type was consistently correct production. Between these two youngest age groups (3 and 4), the only significant difference was in consistently incorrect responses, which the 3-year-olds produced more often than the older children. There was a significant negative correlation between consistently incorrectly produced words and children's phonological skills, but no other relationships were found. The results indicate that when assessing children with speech sound disorder (SSD), Finnish clinicians need to take into account the fact that even 3-year-old typically developing children generally produce words correctly, either consistently or inconsistently.

Interventions for childhood apraxia of speech

BACKGROUND

Childhood apraxia of speech (CAS) affects a child's ability to produce sounds and syllables precisely and consistently, and to produce words and sentences with accuracy and correct speech rhythm. It is a rare condition, affecting only 0.1% of the general population. Consensus has been reached that three core features have diagnostic validity: (1) inconsistent error production on both consonants and vowels across repeated productions of syllables or words; (2) lengthened and impaired coarticulatory transitions between sounds and syllables; and (3) inappropriate prosody (ASHA 2007). A deficit in motor programming or planning is thought to underlie the condition. This means that children know what they would like to say but there is a breakdown in the ability to programme or plan the fine and rapid movements required to accurately produce speech. Children with CAS may also have impairments in one or more of the following areas: non-speech oral motor function, dysarthria, language, phonological production impairment, phonemic awareness or metalinguistic skills and literacy, or combinations of these. High-quality evidence from randomised controlled trials (RCTs) is lacking on interventions for CAS.

OBJECTIVES

To assess the efficacy of interventions targeting speech and language in children and adolescents with CAS as delivered by speech and language pathologists/therapists.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, eight other databases and seven trial registers up to April 2017. We searched the reference lists of included reports and requested information on unpublished trials from authors of published studies and other experts as well as information groups in the areas of speech and language therapy/pathology and linguistics.

SELECTION CRITERIA

RCTs and quasi-RCTs of children aged 3 to 16 years with CAS diagnosed by a speech and language pathologist/therapist, grouped by treatment types.

DATA COLLECTION AND ANALYSIS

Two review authors (FL, AM) independently assessed titles and abstracts identified from the searches and obtained full-text reports of all potentially relevant articles and assessed these for eligibility. The same two authors extracted data and conducted the 'Risk of bias' and GRADE assessments. One review author (EM) tabulated findings from excluded observational studies (Table 1).

MAIN RESULTS

This review includes only one RCT, funded by the Australian Research Council; the University of Sydney International Development Fund; Douglas and Lola Douglas Scholarship on Child and Adolescent Health; Nadia Verrall Memorial Scholarship; and a James Kentley Memorial Fellowship. This study recruited 26 children aged 4 to 12 years, with mild to moderate CAS of unknown cause, and compared two interventions: the Nuffield Dyspraxia Programme-3 (NDP-3); and the Rapid Syllable Transitions Treatment (ReST). Children were allocated randomly to one of the two treatments. Treatments were delivered intensively in one-hour sessions, four days a week for three weeks, in a university clinic in Australia. Speech pathology students delivered the treatments in the English language. Outcomes were assessed before therapy, immediately after therapy, at one month and four months post-therapy. Our review looked at one-month post-therapy outcomes only.We judged all core outcome domains to be low risk of bias. We downgraded the quality of the evidence by one level to moderate due to imprecision, given that only one RCT was identified. Both the NDP-3 and ReST therapies demonstrated improvement at one month post-treatment. A number of cases in each cohort had recommenced usual treatment by their speech and language pathologist between one month and four months post-treatment (NDP-3: 9/13 participants; ReST: 9/13 participants). Hence, maintenance of treatment effects to four months post-treatment could not be analysed without significant potential bias, and thus this time point was not included for further analysis in this review.There is limited evidence that, when delivered intensively, both the NDP-3 and ReST may effect improvement in word accuracy in 4- to 12-year-old children with CAS, measured by the accuracy of production on treated and non-treated words, speech production consistency and the accuracy of connected speech. The study did not measure functional communication.

AUTHORS' CONCLUSIONS

There is limited evidence that, when delivered intensively, both the NDP-3 and ReST may effect improvement in word accuracy in 4- to 12-year-old children with CAS, measured by the accuracy of production on treated and non-treated words, speech production consistency and the accuracy of connected speech. The study did not measure functional communication. No formal analyses were conducted to compare NDP-3 and ReST by the original study authors, hence one treatment cannot be reliably advocated over the other. We are also unable to say whether either treatment is better than no treatment or treatment as usual. No evidence currently exists to support the effectiveness of other treatments for children aged 4 to 12 years with idiopathic CAS without other comorbid neurodevelopmental disorders. Further RCTs replicating this study would strengthen the evidence base. Similarly, further RCTs are needed of other interventions, in other age ranges and populations with CAS and with co-occurring disorders.

A systematic review and classification of interventions for speech-sound disorder in preschool children

BACKGROUND

Multiple interventions have been developed to address speech sound disorder (SSD) in children. Many of these have been evaluated but the evidence for these has not been considered within a model which categorizes types of intervention. The opportunity to carry out a systematic review of interventions for SSD arose as part of a larger scale study of interventions for primary speech and language impairment in preschool children.

AIMS

To review systematically the evidence for interventions for SSD in preschool children and to categorize them within a classification of interventions for SSD.

METHODS & PROCEDURES

Relevant search terms were used to identify intervention studies published up to 2012, with the following inclusion criteria: participants were aged between 2 years and 5 years, 11 months; they exhibited speech, language and communication needs; and a primary outcome measure of speech was used. Studies that met inclusion criteria were quality appraised using the single case experimental design (SCED) or PEDro-P, depending on their methodology. Those judged to be high quality were classified according to the primary focus of intervention.

OUTCOMES & RESULTS

The final review included 26 studies. Case series was the most common research design. Categorization to the classification system for interventions showed that cognitive-linguistic and production approaches to intervention were the most frequently reported. The highest graded evidence was for three studies within the auditory-perceptual and integrated categories.

CONCLUSIONS & IMPLICATIONS

The evidence for intervention for preschool children with SSD is focused on seven out of 11 subcategories of interventions. Although all the studies included in the review were good quality as defined by quality appraisal checklists, they mostly represented lower-graded evidence. Higher-graded studies are needed to understand clearly the strength of evidence for different interventions.

Error Consistency in Acquired Apraxia of Speech With Aphasia: Effects of the Analysis Unit

PURPOSE

Diagnostic recommendations for acquired apraxia of speech (AOS) have been contradictory concerning whether speech sound errors are consistent or variable. Studies have reported divergent findings that, on face value, could argue either for or against error consistency as a diagnostic criterion. The purpose of this study was to explain discrepancies in error consistency results based on the unit of analysis (segment, syllable, or word) to help determine which diagnostic recommendation is most appropriate.

METHOD

We analyzed speech samples from 14 left-hemisphere stroke survivors with clinical diagnoses of AOS and aphasia. Each participant produced 3 multisyllabic words 5 times in succession. Broad phonetic transcriptions of these productions were coded for consistency of error location and type using the word and its constituent syllables and sound segments as units of analysis.

RESULTS

Consistency of error type varied systematically with the unit of analysis, showing progressively greater consistency as the analysis unit changed from the word to the syllable and then to the sound segment. Consistency of error location varied considerably across participants and correlated positively with error frequency.

CONCLUSIONS

Low to moderate consistency of error type at the word level confirms original diagnostic accounts of speech output and sound errors in AOS as variable in form. Moderate to high error type consistency at the syllable and sound levels indicate that phonetic error patterns are present. The results are complementary and logically compatible with each other and with the literature.

Speech Inconsistency in Children With Childhood Apraxia of Speech, Language Impairment, and Speech Delay: Depends on the Stimuli

PURPOSE

The current research sought to determine (a) if speech inconsistency is a core feature of childhood apraxia of speech (CAS) or if it is driven by comorbid language impairment that affects a large subset of children with CAS and (b) if speech inconsistency is a sensitive and specific diagnostic marker that can differentiate between CAS and speech delay.

METHOD

Participants included 48 children ranging between 4;7 to 17;8 (years;months) with CAS (n = 10), CAS + language impairment (n = 10), speech delay (n = 10), language impairment (n = 9), or typical development (n = 9). Speech inconsistency was assessed at phonemic and token-to-token levels using a variety of stimuli.

RESULTS

Children with CAS and CAS + language impairment performed equivalently on all inconsistency assessments. Children with language impairment evidenced high levels of speech inconsistency on the phrase "buy Bobby a puppy." Token-to-token inconsistency of monosyllabic words and the phrase "buy Bobby a puppy" was sensitive and specific in differentiating children with CAS and speech delay, whereas inconsistency calculated on other stimuli (e.g., multisyllabic words) was less efficacious in differentiating between these disorders.

CONCLUSIONS

Speech inconsistency is a core feature of CAS and is efficacious in differentiating between children with CAS and speech delay; however, sensitivity and specificity are stimuli dependent.

Evidence-based intervention for preschool children with primary speech and language impairments: Child Talk – an exploratory mixed-methods study

Background

The Child Talk study aimed to develop an evidence-based framework to support the decision-making of speech and language therapists (SLTs) as they design and plan interventions appropriate to the needs of individual children with primary speech and language impairments and their families. The need for early identification and effective intervention for these children continues to be a government policy priority because of the link between children’s early speech and language skills and their broader well-being and outcomes in later life. The first phase of Child Talk sought to map and describe current SLT practice for these children; identify and summarise the existing research evidence relating to practice; and investigate the perspectives of parents, early years practitioners, preschool children and ‘underserved’ communities on speech and language therapy. The second phase of Child Talk focused on the development of a toolkit – assessment tools, outcome measures and a data set – to support future service and economic evaluations of the framework.

Methods

Child Talk adopted a mixed-methods design. Quantitative methods included surveys and investigated the prevalence and patterns of intervention usage; qualitative data collection methods included focus groups, interviews and reflection to investigate participants’ perspectives and understandings of interventions. Data analysis methods included descriptive and inferential statistics, thematic and content analysis and framework analysis. Participants were recruited nationally through six NHS sites, professional bodies, parent groups and advertising. Participants included SLTs (n = 677), parents (n = 84), preschool children (n = 24), early years practitioners (n = 31) and ‘underserved’ communities (n = 52).

Key findings

Speech and language therapy interventions were characterised in terms of nine themes, viewed as comprehensive and inclusive by practitioners. Relevant assessments, interventions and outcome domains were identified for the nine themes. Areas of tacit knowledge and underspecified processes contributed to variability in the detail of the framework. Systematic reviews identified 58 relevant and robust studies (from 55,271 papers retrieved from the initial literature search). The number of studies relevant to each theme varied from 1 to 33. Observational data on preschool children’s perspectives on speech and language therapy interventions revealed the dynamic nature of their interaction with different activities and people within therapy sessions. Parents’ experiences of speech and language therapy were generally positive although some reported that the rationale for therapy was not always clear. Parental perspectives in underserved communities suggested that, although parents were confident about how to support children’s language development, they were less informed about the nature of language impairments and the function of speech and language therapy. The availability of information regarding resources directed towards speech and language therapy services was poor. In particular, services lacked both a culture of collecting outcome data routinely and measures of professional input and costs associated with their activities.

Conclusion

A descriptive framework of SLT practice has been developed to support the discussions between therapists and families when making decisions regarding the selection of interventions and outcome measures. Further research is needed to address gaps in the intervention framework and evaluate its effectiveness and cost-effectiveness in improving outcomes for preschool children with primary speech and language impairments.

Study registration

This study is registered as PROSPERO CRD42013006369.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Evidence-Based Practice for Children With Speech Sound Disorders: Part 1 Narrative Review

Purpose

This article provides a comprehensive narrative review of intervention studies for children with speech sound disorders (SSD). Its companion paper (Baker & McLeod, 2011) provides a tutorial and clinical example of how speech-language pathologists (SLPs) can engage in evidence-based practice (EBP) for this clinical population.

Method

Studies reporting speech sound intervention for children with SSDs published from 1979 to 2009 were identified and coded.

Results

One hundred thirty-four intervention studies were identified. Intervention typically was conducted by an SLP in a one-to-one individual format for 30- to 60-min sessions 2 to 3 times per week. Total duration of intervention (from assessment to discharge) was reported for 10 studies and ranged from 3 to 46 months. Most studies were either Level IIb (quasi-experimental studies, 41.5%) or Level III (nonexperimental case studies, 32.6%). Single-case experimental design (29.6%) was the most frequently used experimental research design. There were 7 distinct approaches to target selection and 46 distinct intervention approaches, with 23 described in more than 1 publication. Each approach was associated with varying quantities and levels of evidence, according to research design.

Conclusion

Collaborative research reflecting higher levels of evidence using rigorous experimental designs is needed to compare the relative benefits of different intervention approaches.

Intervention for childhood apraxia of speech

BACKGROUND

The diagnostic criteria for Childhood Apraxia of Speech (CAS), and the underlying cause(s) for this disorder, remain heavily debated. Some agreement exists that children with CAS may have impairments in one or more of the following domains: non-speech oral motor function, motor speech function, speech sounds and structures (i.e., syllable and word shapes), prosody, language, phonemic awareness / metalinguistic skills, and literacy . Recently consensus has been reached that only three features across these domains have diagnostic validity: (1) inconsistent error production on both consonants and vowels across repeated productions of syllables or words, (2) lengthened and impaired coarticulatory transitions between sounds and syllables, and (3) inappropriate prosody (ASHA 2007). Perhaps due to the ongoing deliberation over aetiology and diagnosis, little evidence on intervention for CAS is published.

OBJECTIVES

To assess the efficacy of intervention delivered by Speech and Language Pathologists(s)/Speech and Language Therapists targeting CAS in children and adolescents.

SEARCH STRATEGY

The following databases were searched: CENTRAL (Issue 4, 2006), MEDLINE (1966 to 01/2007), CINAHL (1982 to 12/2006), EMBASE (1980 to 01/2007), ERIC (1965 to 01/2007), Linguistics Abstracts Online (1985 to 01/2007), PsycINFO (1872 to 01/2007). Reference lists of articles thus identified were examined.

SELECTION CRITERIA

The review considered randomised controlled trials (RCTs) and quasi-randomised studies of children aged 3 to 16 years with CAS, grouped by treatment types (e.g., perceptual and instrumentally-based biofeedback treatment techniques).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed titles and abstracts identified from the searches and obtained full text versions of all potentially relevant articles. Articles were assessed for design and risk of bias. In addition to outcome data, a range of variables about participant group and outcomes were documented.

MAIN RESULTS

Of 825 titles and abstracts searched, only 31 abstracts appeared to meet inclusion criteria. The remaining 794 papers were excluded predominantly on the basis of not including participants with CAS (e.g., focused on other developmental speech disorders or adult acquired apraxia of speech), or for not being intervention studies (i.e. being diagnostic or descriptive). All 31 full text articles obtained were excluded following evaluation as they did not meet inclusion criteria on design. . Thus no studies are included in this review.

AUTHORS' CONCLUSIONS

The review demonstrates a critical lack of well controlled treatment studies addressing treatment efficacy for CAS, making it impossible for conclusions to be drawn about which interventions are most effective for treating CAS in children or adolescents.

Error consistency and the evaluation of treatment outcomes

The consistency/variability of error substitution patterns may hold important implications for subgrouping children with speech disorders, as well as for relationships between learning and generalization patterns. There is a need to quantify and examine the range of consistency/variability within the speech disordered population as it relates to system-wide change. This investigation compared two groups of preschool children (N = 10 each) differing in the consistency/variability of errors on a variety of pre-treatment and treatment outcome measures. The Error Consistency Index (ECI), a measure of error variability across the entire phonological system, was used to identify groups at the extreme ends of the ECI distribution from a larger participant pool. Each participant was treated on three target singletons from among obstruents /s, z, f, integral, tintegral, k, g/ and liquids /l, r/ and change on these targets, as well as their generalization to untrained positions was assessed. Although there were significant differences between the variable and consistent groups on all pre-treatment measures, there were no significant group differences in target and generalization learning or in per cent consonants correct (PCC) change. These findings provide evidence to suggest that relationships observed between error variability for individual phonemes and learning of those targets may differ from those observed when consistency/variability is quantified for the entire system and change across a number of phonemes, and the system as a whole, is examined.

Intervention for children with severe speech disorder: a comparison of two approaches

BACKGROUND

Children with speech disorder are a heterogeneous group (e.g. in terms of severity, types of errors and underlying causal factors). Much research has ignored this heterogeneity, giving rise to contradictory intervention study findings. This situation provides clinical motivation to identify the deficits in the speech-processing chain that underlie different subgroups of developmental speech disorder. Intervention targeting different deficits should result in a differential response to intervention across these subgroups.

AIMS

To evaluate the effect of two different types of therapy on speech accuracy and consistency of word production of children with consistent and inconsistent speech disorder.

METHODS & PROCEDURES

Eighteen children (aged 4;08-6;05 years) with severe speech disorder participated in an intervention study comparing phonological contrast and core vocabulary therapy. All children received two 8-week blocks of each intervention. Changes in consistency of production and accuracy (per cent consonants correct) were used to measure the effect of each intervention.

OUTCOMES & RESULTS

All of the children increased their consonant accuracy during intervention. Core vocabulary therapy resulted in greater change in children with inconsistent speech disorder and phonological contrast therapy resulted in greater change in children with consistent speech disorder.

CONCLUSIONS

The results provide evidence that treatment targeting the speech-processing deficit underlying a child's speech disorder will result in efficient system-wide change. Differential response to intervention across subgroups provides evidence supporting theoretical perspectives regarding the nature of speech disorders: it reinforces the concept of different underlying deficits resulting in different types of speech disorder.

Diagnostic criteria of developmental apraxia of speech used by clinical speech-language pathologists

The diagnostic criteria used to identify developmental apraxia of speech (DAS) have been at the center of controversy for decades. Despite the difficulty in determining the characteristics that differentiate DAS from other speech acquisition disorders, many children are identified with this disorder. The current report presents the criteria used by 75 speech-language pathologists to establish a diagnosis of DAS. Although 50 different characteristics were identified, 6 of these characteristics accounted for 51.5% of the responses. These characteristics included inconsistent productions, general oral-motor difficulties, groping, inability to imitate sounds, increasing difficulty with increased utterance length, and poor sequencing of sounds. These results are consistent with the general ambiguity of the diagnostic criteria of DAS and suggest that no single deficit is used among clinicians.