Last month we shared research showing that parent ratings of stuttering severity were related to results on the Test of Childhood Stuttering. Now, these researchers out of Australia (home of the Lidcombe Program), analyzed data from three previous randomized controlled trials of that intervention with an eye to the outcome measures. They found that there was “no statistical reason to favor” the gold-standard Percent Syllables Stuttered (PSS) over a much easier, much faster parent-reported severity rating, on a scale of 1 (no stuttering) to 10 (extremely severe stuttering), as observed over the previous week. Not only were the ratings much simpler to collect for the preschool population studied, they have the advantage of capturing the whole week vs. one quick sample. Now, the paper specifically suggests that other researchers use the ratings over PSS as a way to make stuttering intervention research easier to do, but if anyone needs a faster outcome measure, it’s practicing clinicians, amiright? Depending on where you work, you may be required to use PSS to qualify kids for services, but these findings could come in handy when special circumstances require you to “override” the eligibility criteria. You can also use severity ratings to track progress, and save a LOT of time over counting syllables.
Note that for children with fairly mild stuttering, neither measure shows progress all that well. From 3% to 2% syllables stuttered, or a parent waffling between a rating of “1” and “2”... you may have to get creative to show the results of treatment. For kids with more severe stuttering, either measure works well. Don’t use them interchangeably, though—pick a method and stick with it.
Onslow, M., Jones, M., O’Brian, S., Packman, A., Menzies, R., Lowe, R., … Franken, M.C. (2018). Comparison of Percentage of Syllables Stuttered With Parent-Reported Severity Ratings as a Primary Outcome Measure in Clinical Trials of Early Stuttering Treatment. Journal of Speech, Language, and Hearing Research. Advance online publication. doi:10.1044/2017_JSLHR-S-16-0448.