Speech and language therapists' insights into severity of speech sound disorders in children for developing the speech sound disorder severity construct

Background

Children with speech sound disorders (SSD) are at higher risk of communication breakdown, but the impact of having an SSD may vary from child to child. Determining the severity of SSD helps speech-language therapists (SLTs) to recognise the extent of the problem and to identify and prioritise children who require intervention.

Aims

This study aimed to identify severity factors for SSD in order to develop a multifactorial Speech Sound Disorder Severity Construct (SSDSC) using SLTs’ views and the International Classification of Functioning, Disability and Health (ICF).

Method

In an explorative five-staged qualitative study, the research question was answered: ‘How do SLTs determine the severity of SSD in children?’. A total of 91 SLTs from The Netherlands participated in data collection and analysis. The iterative process included three different qualitative research methodologies (thematic analysis [TA], constructivist grounded theory [CGT] and content analysis [CA]) to ensure validation of the results by means of method triangulation.

Results

SLTs considered nine themes: intelligibility, speech accuracy, persistence, the child's perception, impact, communicative participation, concomitant factors, professional point of view, and environmental factors. The themes were summarised in three main severity factors: (I) Speech accuracy, (II) The child's perception of the impact of their speech, and (III) Intelligibility in communication. Other severity factors were concomitant factors and impact. Expertise and support were identified as facilitators or barriers that may worsen or relieve the severity of SSD.

Conclusions

This study highlights the need for SLTs to rethink how they think about severity as a simplistic construct reflecting only speech accuracy. It is recommended that a broader holistic approach to measuring severity is adopted.

WHAT THIS PAPER ADDS

What is already known on the subject

• Although there are several proposals aiming to define the severity of SSD, the extent to which these align with clinical practice is not well understood. In recent years, speech accuracy and other factors such as intelligibility have been suggested as possible indicators of SSD severity. Flipsen et al. (2005) concluded that experienced clinicians evaluated the number, type and consistency of speech errors as well as intelligibility, considering articulatory competence at both the segmental and whole word level when determining severity. Enderby et al. (2013) developed ICF-based Therapy Outcome Measures (TOMs), including a TOM for phonological disorder. Although there is evidence in the literature that multiple factors should be considered when determining severity, there is still no clear guidance on this. In this discussion, the perspective of SLTs is an important contribution to the development of a measure of severity, but is lacking in the known literature.

What this paper adds to the existing knowledge

• As a first step, this study examines SLT's perspectives on how they define and measure severity of SSD, and determines how those views align with the ICF in order to develop a severity construct that can be further tested and validated. Using the views of SLTs and the ICF, this qualitative study resulted in the multifactorial SSDSC.

What are the potential or actual clinical implications of this work?

• The practical experience of SLTs, combined with what is known from the literature, provides insight into the different factors that may contribute to severity of SSD. These factors may be considered in developing a measure of SSD severity in the future.