Comparison of Percentage of Syllables Stuttered With Parent-Reported Severity Ratings as a Primary Outcome Measure in Clinical Trials of Early Stuttering Treatment Academic Article uri icon

abstract

  • Purpose:This report investigates whether parent-reported stuttering severity ratings (SRs) provide similar estimates of effect size as percentage of syllables stuttered (%SS) for randomized trials of early stuttering treatment with preschool children. Method:Data sets from 3 randomized controlled trials of an early stuttering intervention were selected for analyses. Analyses included median changes and 95% confidence intervals per treatment group, Bland-Altman plots, analysis of covariance, and Spearman rho correlations. Results:Both SRs and %SS showed large effect sizes from pretreatment to follow-up, although correlations between the 2 measures were moderate at best. Absolute agreement between the 2 measures improved as percentage reduction of stuttering frequency and severity increased, probably due to innate measurement limitations for participants with low baseline severity. Analysis of covariance for the 3 trials showed consistent results. Conclusion:There is no statistical reason to favor %SS over parent-reported stuttering SRs as primary outcomes for clinical trials of early stuttering treatment. However, there are logistical reasons to favor parent-reported stuttering SRs. We conclude that parent-reported rating of the child's typical stuttering severity for the week or month prior to each assessment is a justifiable alternative to %SS as a primary outcome measure in clinical trials of early stuttering treatment.

authors

  • Onslow, Mark
  • Jones, Mark
  • O'Brian, Sue
  • Packman, Ann
  • Menzies, Ross
  • Lowe, Robyn
  • Arnott, Simone
  • Bridgman, Kate
  • de Sonneville, Caroline
  • Franken, Marie-Christine

publication date

  • 2018