Treating Childhood Apraxia of Speech: Evaluating the Kaufman Speech to Language Protocol

Abstract

A Cochrane review of the treatments used for childhood apraxia of speech (CAS) in 2009 identified the need for more well controlled studies (Morgan & Vogel, 2009). These same recommendations were echoed when the review was completed again in 2018 (Morgan, Murray & Liegeois, 2018). There is currently no gold-standard intervention recommended for children with CAS (Morgan et al., 2018). Since the first Cochrane study was published, research has been conducted to examine a small range of treatment approaches for CAS. Despite the increased publication of treatment research, speech-language pathologists continue to use treatment approaches that are not supported with empirical evidence. The Kaufman Speech-Language Protocol (K-SLP) is a treatment approach that uses successive approximations to improve speech in children with CAS (Kaufman, 2014). At the commencement of this PhD there was no published evidence for the K-SLP. The overall aim of this thesis is to investigate the effectiveness of the K-SLP. To do this, five research studies have been completed.

It is imperative to determine what speech-language pathology clinicians currently use to treat CAS in a clinical setting, and the proportion of speech-language pathologists that use the K-SLP to treat CAS. These questions were investigated quantitatively using survey research. The surveys also sought to establish what training, if any, the speech-language pathologists obtained prior to implementing a treatment approach, and whether they administered the treatment according to available protocols.

Following these studies, three treatment studies using single case experimental design method were conducted to evaluate the K-SLP. Participants for each of these studies were assessed to confirm their diagnosis of CAS using the diagnostic criteria outlined by the American Speech-Language-Hearing Association (ASHA), childhood apraxia of speech (CAS) technical report (ASHA, 2007). Treatment was provided according to a standardised treatment protocol by either the primary investigator or by trained student clinicians. The result of the three studies is an operationalised protocol for delivering the K-SLP. An additional two chapters exploring results across the three treatment studies are included. The results of our post-hoc analyses indicates that inconsistency should be used as an outcome measure to assess the effectiveness of CAS interventions. Additionally, it was found that the statistical analysis used to measure clinically relevant changes (i.e., effect sizes) impacted the evaluation of clinical research, therefore effect sizes that take into account children’s variable production at baseline (a common feature of CAS; see ASHA, 2007) should be used.

The research conducted indicated that the K-SLP was frequently used to treat CAS in the US. Results from the three treatment studies showed that the K-SLP was effective in improving the articulatory accuracy and speech consistency of children with CAS.