Introduction

Children with speech sound disorders (SSDs) make up the majority of speech-language pathology caseloads. In light of this information it is critical that speech-language pathologists (SLPs) carry out consistent base assessments and treatment interventions to ensure maximum use of the limited resources available to these children. Any speech-language pathologist (SLP) can attest to the fact that there are mass shortages of SLPs in Canada and that they have unmanageable caseloads. SLPs must engage in the most efficient methods to provide service to all clients in order to increase the quality of therapy outcomes and to assist with caseload management decisions (Rvachew, 2006).

Assessment, caseload management and therapy outcome research

Effective management of SSDs is important because this is the most commonly occurring communication disorder. Furthermore, children presenting with a speech sound disorder (SSD) are at risk for social and reading difficulties in the school setting (Lewis, 2007). Adults with a history of SSD are more likely to complete fewer years of formal education and often obtain occupations that require fewer skills. Given the possible significant impact of SSD, there is a great need for accurate early intervention to reduce the number of impacted children. There is also a critical need within the field of speech-language pathology to use evidence-based practices to make informed decisions regarding waitlist management and intervention choices to produce the most positive outcomes.

Prior to intervention, a comprehensive standardized assessment must be completed to establish diagnostic baselines. The assessment should include identification of sound errors and sound deviation types, a metaphonological assessment, as well as intelligibility and stimulability ratings. It should also include a case history, a language assessment, a hearing evaluation and an oral mechanism evaluation. Finally, a continuous speech sample should be recorded for baseline purposes (Prezas & Hodson, 2007). After the initial diagnostic assessment, ongoing assessment is necessary in order to document changes and progress in the child’s speech development. Standardization of assessments in the field may allow researchers to more readily obtain data from intervention of more homogenous groupings.

The outcome of assessment for SSD should result in one of three standard diagnoses. The three diagnostic labels are: articulation disorder (indicating misarticulation of one or two specific speech sounds), suspected childhood apraxia (indicating a motor planning disorder with the term “suspect” used because there is poorly agreed upon criteria for this diagnosis) and phonological disorder (indicating errors involving more than one sound and forming a phonological pattern). Once a diagnosis is made, the level of severity and prognosis are identified and possible etiological factors should be noted (Prezas & Hodson, 2007).

Following standardized assessment, a purposed intervention approach based on present research findings which relate to treatment outcomes should be determined (Rvachew, 2006). Research findings indicate that targeting speech sound error patterns is more effective than targeting specific speech errors one at a time. Children presenting with SSD must be taught to hear or discriminate the differences between the accurate sound and the error production in order to potentially double positive treatment outcomes. It is important to reinforce the need to have high success and accuracy on a small stimuli set rather than extensive variation in therapy activities and materials. Utililization of minimal pairs within the context of intervention is supported as an effective therapy tool as long as the child can accurately discriminate the target sound and make correct phonetic placement. Phonetic placement does not include oral motor exercises which have been shown as ineffective. There is also evidence that positive outcomes result from the use of technologies to provide visual feedback for articulation practice during intervention activities. Finally, the intervention must be sufficiently intense to ensure a good outcome. Current research indicates that on average 20 hours of speech intervention over a period of 15 weeks is the minimum requirement to produce notable changes in a child's speech patterns. The amount of intervention that the child receives can be augmented by providing parents with a home program to supplement the services provided directly by the SLP.

In practice, most SLPs would find it difficult to implement speech therapy programs that are consistent with the research evidence. Currently, in most clinical and school settings, the use of para-professionals to deliver intervention is the wide spread. These individuals often come to the job with little or no experience and require on the job training and education. Experience has shown that outcomes in the school setting are often highly correlated with the quality of the service that is delivered by para-professionals. This quality is judged based on para-professional’s understanding of target goals, hierarchy of “sub and super” steps within goals as well as their ability to deliver accurate feedback within the appropriate target goal level. Speech-Language Pathologists are most often challenged to outline therapy at a very basic level in order to begin service delivery in a timely manner. Consequently the usual chosen intervention method is an articulation approach that targets a single speech sound because this type of program can be outlined and followed in a systematic manner. Para-professionals are able to begin teaching sounds with visual placement (e.g., ‘f’, ‘s’, ‘th’) but often require more education to develop accurate feedback for children working on less visible sounds such as /r/. Teaching difficult sounds such as /r/ may be enhanced by the use of computer technologies to provide visual feedback. Unfortunately, technologies such as spectography and electropalatography are not readily available and are unlikely to be implemented in school settings. Furthermore, even if these technologies were available, it is unlikely that they could be used by paraprofessionals.

The shortage of SLPs also ensures that most children are not receiving the minimum 12 to 15 hours of direct speech therapy that is recommended on the basis of research evidence. In most school settings a block system of service delivery has been implemented to manage the increase in caseload numbers. These block rotations in the past have not been scheduled based on research but rather on trying to deliver equitable service to the population within various school districts. It will be important in the future to ensure that base blocks of service are at least 4-5 months long and that clients are receiving at least one hour of service weekly. At present, many SLPs continue to see more children than can be scheduled using these guidelines in order to give at least some therapy to more children. It is clear that giving minimal therapy will be ineffective and is ultimately a poor use of scarce resources. Home programming has been suggested as a means to extend services to more children. In most school therapy programs, parental involvement is minimal therefore relying on this as a viable service delivery extension may be unreasonable.

Conclusions

Based on the conclusions from research in the area of SSD, clinicians globally as a profession need to identify more standards of practice in the area of SSD. Standardization will result in more consistent delivery of both assessment and treatment, and ultimately in positive treatment outcomes. The clinicians’ assessments need to be consistent in format, outcome diagnosis, and in their inclusion of additional areas of assessment of concomitant disorders. The assessments also need to provide information to assist with the direction of subsequent intervention. Intervention that follows needs to be supported by evidence-based practices which will ensure the integrity of treatment within a reasonable time period. Para-professional service providers need more intense training focused on a phonological approach to intervention and ongoing clinical skill development.

Future considerations

It is clear from all readings and from incidental reports from colleagues in the field that there is an urgent need for additional research in the area relating to SSD. Specifically, research is needed to investigate whether there is a correlation between etiology of the SSD and the outcome of intervention (Rvachew, 2006). Research also needs to be conducted to determine if genetic factors, co-morbidity of language or cognitive delay as well as dyslexia and ADHD have an effect on intervention outcomes (Lewis, 2007). Studies are also needed to evaluate whether etiology will affect the decisions made regarding the types of intervention approaches that should be utilized. Research is needed to determine the effect of intervention on long-term functional skills development and maintenance.

Finally further research is needed to determine if there is a definitive correlation between para-professional education and treatment outcomes. If research is conducted, professional governing bodies could develop guidelines of service delivery which would ultimately assist with maximizing clinician resources. These guidelines would ensure that clinicians could deliver evidence based intervention through trained para-professionals which would increase the eventual outcome of all therapy efforts. The difficulty in realizing the implementation of these guidelines will directly relate to the shortage of trained personnel and differing work site standards within which many Speech-Language Pathologists operate.