Strengthening intervention trials for children and adolescents who stammer

An exciting new paper was published by Dr Hilde Hofslundsengen (pictured above with Ria) and colleagues from Norway, which looks at the delivery of therapy approaches in clinical trials and provides some real food for thought on how we can strengthen research in the field.

There are many therapy approaches available to support children and adolescents who stammer. Researchers run clinical trials to evaluate the effectiveness of certain treatments or interventions – and many have been published by researchers in the world of stammering. However, it is really important that these clinical trials are of high quality to ensure that the effect of the intervention can be attributed to that intervention and is not the result of other factors. For example, if a research study finds poor outcomes associated with an intervention, this may suggest that the intervention is not effective at achieving it’s objective. Alternatively, it may reflect poor implementation of the intervention. This new paper evaluates the implementation quality of previous clinical trials of stammering interventions – and the findings are really interesting…

What do we mean by implementation quality?

Here, we’re talking about the quality of how a therapy approach is implemented (or delivered) in clinical trials. This includes the training provided to clinicians and/or parents; the ways in which intervention programmes are adapted to individual needs during the trial; planned dosage (e.g. number of sessions); whether the stipulated dosage was adhered to; and the ways in which sessions were monitored during the trial.

So why is implementation quality important? Research has shown that implementation quality is associated strongly with trial outcomes. Consequently, it is an important factor when evaluating how effective that intervention is.

What did they do?

In the current paper, the authors address several research questions but I’m only going to talk about the findings of their first question here (you can read about what else they found out in the paper).

Hofslundsengen et al. (2022) reviewed 21 studies of clinical trials with children and adolescents who stammer, which were published between 1974 and 2019. They recorded whether the published papers had included the following elements of implementation quality:

  • Description of the therapy approach
  • Method of delivery of the therapy approach and support provided to the individual delivering it, e.g. the Speech and Language Therapist, parent, researcher, etc.
  • Specification of how the approach should be delivered, e.g. the number, length and frequency of sessions and whether these were adhered to
  • Whether the programme was adapted during the trial
  • How intervention sessions were monitored, e.g. were they recorded or observed in person?

What did they find?

The big finding was that across the 21 studies, there was substantial variation in the level of detail provided about how interventions were implemented. Here are a few of the key discussion points:

  • The level of detail included about how to carry out the intervention varied – this is important because other researchers might want to replicate the study to see if they find the approach as effective with another population.
  • Many studies did not talk about how therapy sessions were monitored, which is necessary to check that the therapy is being implemented as intended.
  • There was limited information about the training provided to clinicians in many studies – training clinicians in the approach helps to reduce variability in how it is delivered so we can more accurately evaluate the effectiveness of it.

What do the authors recommend?

Hofslundsengen et al. (2022) conclude that there is a need for clearer guidelines for running clinical trials of stammering interventions. Helpfully, they go even further though!

They have developed a checklist for researchers to use when designing and reporting on future clinical trials. They hope that such a checklist will enhance implementation quality, which will help clinicians to make more informed decisions about management of children and adolescents who stammer.

If you would like to read the paper in its entirety, you can follow the link below:

Hofslundsengen, H., Kirmess, M., Guttormsen, L. S., Bottegaard Næss, K.A., Kefalianos, E., (2022). Systematic review of implementation quality of non-pharmacological stuttering intervention trials for children and adolescents, Journal of Fluency Disorders.

Ria Bernard

PhD student, UCL



    Can we sign you up to our newsletter?

    Who are you?
    *Please make sure to check your spam folder once you have signed up to make sure the newsletters are sent to your main inbox

    Please tick the following boxes to opt-in and give consent to the communication channels we can contact you through. Please note, you will need to tick email in order to receive our monthly newsletter:

    Help shape the future of stammering research