Model predicts stuttering and fluency in school-age children
MedWire News: Children can be successfully screened for stuttering and fluency using Howell and Davis's risk factor model, particularly when whole-word repetitions are excluded, UK study findings indicate.
In 2011, Howell and Davis developed a model for assessing stuttering prognosis in children aged 8 years, examining seven risk factors: head injury; age at onset of stuttering; family history; handedness; speaking two or more languages in the preschool years; gender; and stuttering severity. Of these, only severity scores on the Stuttering Severity Instrument for Children and Adults, Third Edition (SSI-3) predicted whether children who stutter (CWS) would recover or still stutter when a teenager.
To develop and assess models for screening stuttering, Peter Howell, from University College London, studied stuttering and severity scores from CWS and fluent children aged 8-10 years, with 222 and 103 children, respectively, recruited for the development phase and 272 and 25 children, respectively, recruited for the validation phase.
A series of models were developed for screening and predicting the prognosis of CWS and fluent children, with analyses conducted with whole-word repetitions excluded and included in the SSI-3. The model that excluded whole-word repetitions was tested in children from a range of ages.
The results, reported in the Journal of Fluency Disorders, show that all the models tested achieved a specificity and sensitivity of approximately 80%. For the model using the SSI-3 without whole-repetition, the overall percentage of correct identifications was 81.1%.
Overall classification accuracy was 87.1% and 82.2% when SSI-3 was used with or without whole-word repetition, respectively. The sensitivity in identifying CWS who would recover was 81.3%, and the specificity in finding CWS who persisted with stuttering was 80.9%. These mirror the findings of the previous study.
In the validation study, the model of SSI-3 without whole-word repetition correctly identified 84.4% of fluent children and 88.0% of CWS, some of whom differed in age from those used to develop the model.
Howell concludes: "The findings show that Howell and Davis's (2011) model for predicting risk of stuttering can be successfully adapted to classify fluent children.
"This offers the possibility of it acting as a screening instrument for stuttering with children at the age of school intake. The model is successful at classifying CWS outside the age range for which it was originally developed."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Liam Davenport, MedWire Reporter