Investigating the Lidcombe Program of early stuttering intervention for preschool age children when parental verbal contingencies for fluent and stuttered moments are removed.

The Lidcombe Program (LP) is currently the most efficacious treatment for the early intervention of stuttering. Components of LP as described in the treatment manual (Packman et al, 2011) consist of parent verbal contingencies (PVCs), measurement of stuttering, weekly visits with a speech pathologist, treatment in structured and unstructured conversations. Despite being primarily described as an operant treatment, it is not known whether the operant verbal contingencies are the active agent in the program. During treatment, parents are taught how to provide verbal contingencies directly following stutter-free and stuttered speech. There are three contingencies for stutter-free speech: 1. Acknowledgement 2. Praise, and 3. Request for self-evaluation of stutter-free speech; and two contingencies for instances of stuttered speech: 1. Acknowledgement 2. Request for self-correction of the unambiguous stutter. In order to provide these responses successfully, the parent is taught by the clinician to provide PVCs in ‘structured’ tasks and ‘unstructured’ conversations. The parent is also taught how to rate the child’s stuttering severity, how to recognise types of stutters and given advice on how to alter treatment when necessary to maintain stutter-free speech as much as possible. Despite the proven efficacy of LP, little is known about which components are essential for the outcome. Initial critics of LP expressed concerns that PVCs may be harmful to the child, however these claims have since been disproven. The role of PVCs from the parent’s perspective has been investigated in many studies. While themes regarding the use of PVCs in these studies are generally positive, each study has revealed participants that have struggled with the use of PVCs. These studies show that some parents have difficulty delivering PVCs, and some children respond negatively to PVCs. Other smaller studies have displayed that children decreased stuttering whether or not the parent was taught to use PVCs (Harrison et al, 2004). In another preliminary study comparing LP with a Demands and Capacities approach (containing no direct contingencies for stuttering) nil difference was found between both groups after 12 weeks of therapy (Franken, Schalk & Boelens, 2005). Further, in a small study of three parent/child pairs, Carr-Swift et al (2011), showed that parent compliance with delivery of PVCs may not always reflect correct practice. In the current study, the number, frequency and duration of clinic visits and intervention is not expected to be different across both treatment arms. Lidcombe Program clinic visits are usually between 45 and 60 minutes in duration. Investigators anticipate that while the removal of one component may reduce the duration of individual clinic visits, this will not be known until the study has reached completion. Determining the role of PVCs may help to reduce the load for parents in their delivery of the program and if PVCs are shown to slow progress, their removal may possibly make therapy more efficient and lead to better provision of services. Provided participants meet criteria for the study and are able to commit to study protocols, children and their parents will be seen for treatment weekly until the child displays no stuttering or very little stuttering. This varies for every child and may be dependent on other factors such as the severity of the child's stutter. Once near normal fluency is achieved, there is a period of programmed maintenance of fluency, with a gradual reduction in clinic visits as required to maintain fluency for approximately one year. In this study, the final data point will be at 18 months after the first clinic visit. It is presumed that most children will have completed therapy at this time.