Why do we need evidence-based interventions for preschool speech sound disorders?
Speech sound disorders (SSD) represent one of the most common communication difficulties in early childhood, affecting approximately 10-25% of preschool-aged children. The impact of these disorders can be far-reaching, potentially affecting literacy development, academic achievement, social interactions, and psychological wellbeing. As paediatric speech pathologists, we are tasked with making critical decisions about which intervention approaches to implement with young children. These decisions should ideally be guided by robust, high-quality evidence. However, the landscape of interventions for SSD is vast and varied, making it challenging to navigate without a comprehensive understanding of the evidence base.
A 2018 systematic review by Wren, Harding, Goldbart and Roulstone provides valuable insights into this landscape by systematically evaluating and classifying interventions for preschool children with SSD. Published in the International Journal of Language & Communication Disorders, this review represents an important contribution to our understanding of evidence-based practice in paediatric speech pathology. As a clinician and researcher working with children with communication disorders in Australia, I find this review particularly relevant to our practice. Let’s explore its findings and implications in detail.
What is the current landscape of interventions for speech sound disorders in preschool children?
The systematic review by Wren and colleagues identified 26 high-quality studies focused on interventions for preschool children with SSD. These studies employed various methodologies, with case series being the most common research design. This finding itself is noteworthy, as case series typically represent lower levels of evidence in the hierarchy of research designs compared to randomised controlled trials or well-designed cohort studies.
The interventions examined across these studies were diverse, reflecting the multifaceted nature of both speech sound disorders and approaches to remediation. The authors categorised these interventions using a classification system that encompassed 11 subcategories. Interestingly, the review found that the published evidence was concentrated in just seven of these subcategories, suggesting gaps in our knowledge about certain intervention approaches.
In the Australian context, this finding is particularly relevant as it highlights the need for critical evaluation of our intervention choices. Speech pathologists across Australia, whether working in public health settings, private practice, or through the National Disability Insurance Scheme (NDIS), need to be aware that some commonly used intervention approaches may have limited research evidence supporting their effectiveness.
How were interventions classified and evaluated in this systematic review?
Wren and colleagues employed a methodical approach to categorising and evaluating interventions. Studies published up to 2012 were included if they focused on children aged between 2 years and 5 years, 11 months, who exhibited speech, language and communication needs, and where a primary outcome measure of speech was used.
The quality of each study was appraised using appropriate tools: the Single Case Experimental Design (SCED) scale for single case studies and the PEDro-P scale for group design studies. This rigorous approach to quality appraisal ensured that only methodologically sound studies were included in the final analysis.
The classification system used in the review provides a useful framework for conceptualising different intervention approaches. The 11 subcategories likely encompass distinctions between intervention philosophies (e.g., motor-based vs. linguistic approaches), specific techniques, and theoretical underpinnings. For clinicians in practice, this classification system offers a structure for reflecting on our intervention choices and considering whether we are drawing from a range of evidence-based approaches or perhaps over-relying on certain categories.
Which intervention approaches have the strongest evidence base?
The review findings indicate that cognitive-linguistic and production approaches to intervention were the most frequently reported in the literature. Cognitive-linguistic approaches focus on a child’s underlying phonological knowledge and processing, while production approaches emphasise the physical articulation of speech sounds.
However, interestingly, the highest-graded evidence was found for studies within the auditory-perceptual and integrated categories. Auditory-perceptual interventions target a child’s ability to perceive and discriminate speech sounds, while integrated approaches combine elements from multiple intervention categories.
This distinction between frequency of study and quality of evidence is crucial for clinical practice. In Australia, where evidence-based practice is increasingly emphasised across healthcare settings, speech pathologists should note that the most commonly studied interventions may not necessarily have the strongest evidence base.
The finding that integrated approaches were among those with the highest-graded evidence aligns with contemporary clinical thinking about individualised, comprehensive intervention. At Speech Clinic and similar practices across Australia, many speech pathologists adopt an eclectic approach that draws from multiple intervention philosophies tailored to each child’s specific pattern of strengths and needs.
What are the gaps in our current understanding of SSD interventions?
Despite the valuable insights provided by the review, several important gaps in our knowledge are evident. First, the authors note that while all included studies were of good quality according to the appraisal checklists, they mostly represented lower-graded evidence in the broader hierarchy of evidence. This suggests a need for more high-quality research employing rigorous methodologies such as randomised controlled trials.
Second, the evidence was concentrated in only seven of eleven subcategories, indicating that some intervention approaches remain under-researched. This is particularly relevant in the Australian context, where innovative approaches continue to emerge, including those incorporating digital technology and telehealth delivery—a growing area of practice at Speech Clinic and similar services.
Third, the review included studies published up to 2012, meaning that more recent research findings are not captured. Since 2012, numerous studies have been published that may provide additional insights into the effectiveness of various intervention approaches. This highlights the importance of continuing education and staying abreast of emerging evidence.
Another significant gap relates to intervention intensity and dosage. The review does not specifically highlight findings regarding optimal treatment frequency, session duration, or total intervention period—factors that are highly relevant to clinical practice and service delivery planning.
How can these findings inform clinical decision-making in paediatric speech pathology?
For Australian speech pathologists working with preschool children with SSD, this review offers several practical implications for clinical decision-making:
- Evidence-informed approach selection: The findings suggest that we should particularly consider auditory-perceptual and integrated approaches, which had the highest-graded evidence. However, cognitive-linguistic and production approaches also have substantial evidence and may be appropriate depending on the child’s presentation.
- Comprehensive assessment: Given the range of intervention subcategories, comprehensive assessment is essential to determine which approach(es) might best address a child’s specific speech sound difficulties.
- Balanced clinical reasoning: While evidence is a crucial component of clinical decision-making, we must balance research findings with clinical expertise and family preferences. The relative lack of high-grade evidence across all intervention subcategories means that clinical judgement remains vital.
- Telehealth considerations: For services like Speech Clinic that provide telehealth services, it’s important to consider how different intervention approaches translate to online delivery. Some approaches may require adaptation, while others may be well-suited to telehealth formats.
- Parent/carer involvement: Given the limitations in service frequency often experienced in the Australian context, approaches that effectively incorporate parent/carer implementation may be particularly valuable.
- Ongoing monitoring and adjustment: The varied evidence base emphasises the importance of closely monitoring intervention outcomes and being prepared to adjust approaches if progress is limited.
Moving forward with evidence-based SSD interventions
The systematic review by Wren and colleagues provides a valuable foundation for understanding the evidence base for SSD interventions in preschool children. However, it also highlights the need for continued research and critical evaluation of our clinical practices.
As speech pathologists, we should strive to contribute to this evidence base through participation in research, careful documentation of outcomes, and sharing of clinical insights. The children and families we serve deserve interventions that are not only theoretically sound but empirically supported.
The findings from this review reinforce the importance of individualised intervention planning based on comprehensive assessment and sound clinical reasoning. They also highlight the potential value of integrated approaches that draw from multiple intervention subcategories to address the unique profile of each child with SSD.
If you or your child need support or have questions about speech sound disorders, please contact us at Speech Clinic.
What is the difference between cognitive-linguistic and production approaches to speech sound disorders?
Cognitive-linguistic approaches focus on improving a child’s phonological knowledge and processing of speech sounds as abstract units in the language system. This might involve activities targeting phonological awareness, sound categorisation, or phonological patterns. Production approaches, by contrast, concentrate on the physical articulation of speech sounds, often involving direct instruction and practice of articulatory movements and positioning.
How do I know which intervention approach is best for my child’s speech sound disorder?
The best intervention approach depends on several factors, including your child’s specific speech error patterns, age, attention and engagement, and overall communication profile. A comprehensive assessment by a speech pathologist is essential for determining the most appropriate approach. The research suggests that integrated approaches, which combine elements from different intervention categories, may be particularly effective for many children.
How long does speech sound disorder intervention typically take?
The duration of intervention varies considerably depending on the severity of the disorder, the specific sounds affected, the child’s age and readiness for intervention, and the consistency of practice between sessions. Some children may make significant progress in 8-12 weeks, while others may benefit from longer periods of intervention. Regular reviews of progress help determine when goals have been achieved or when approaches need adjustment.
Can speech sound disorder interventions be effectively delivered via telehealth?
Yes, research increasingly supports the effectiveness of telehealth delivery for many speech sound disorder interventions. With appropriate technology, materials, and parent/carer involvement, interventions can be successfully adapted to online formats. This is particularly valuable for families in regional or remote areas of Australia, or those with scheduling constraints that make in-person sessions challenging.
What role do parents play in speech sound disorder interventions?
Parents and carers play a crucial role in supporting speech sound intervention. Research suggests that regular practice between therapy sessions significantly enhances outcomes. Speech pathologists typically provide guidance on home practice activities that reinforce therapy targets in everyday contexts. The extent of parent involvement may vary depending on the specific intervention approach, but generally, parents are essential partners in the intervention process.
