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Prevalence and Predictors of Persistent Speech Sound Disorder at Eight Years Old: Findings From a Population Cohort Study

2 September 2016

Yvonne Wren's recent pulication 'Prevalence & Predictors of Persistent Speech Sound Disorder at Eight Years Old: Findings from a Population Cohort Study, was tweeted from JSLHR on 5th August which said it was the most read paper as of that day!

Purpose The purpose of this study was to determine prevalence and predictors of persistent speech sound disorder (SSD) in children aged 8 years after disregarding children presenting solely with common clinical distortions (i.e., residual errors).

Method Data from the Avon Longitudinal Study of Parents and Children (Boyd et al., 2012) were used. Children were classified as having persistent SSD on the basis of percentage of consonants correct measures from connected speech samples. Multivariable logistic regression analyses were performed to identify predictors.

Results The estimated prevalence of persistent SSD was 3.6%. Children with persistent SSD were more likely to be boys and from families who were not homeowners. Early childhood predictors identified as important were weak sucking at 4 weeks, not often combining words at 24 months, limited use of word morphology at 38 months, and being unintelligible to strangers at age 38 months. School-age predictors identified as important were maternal report of difficulty pronouncing certain sounds and hearing impairment at age 7 years, tympanostomy tube insertion at any age up to 8 years, and a history of suspected coordination problems. The contribution of these findings to our understanding of risk factors for persistent SSD and the nature of the condition is considered.

Conclusion Variables identified as predictive of persistent SSD suggest that factors across motor, cognitive, and linguistic processes may place a child at risk.

Despite variation in the rate of speech development, most children who are native speakers of English master accurate production of all vowels and consonants by age 8 years (Dodd, Hulm, Hua, & Crosbie, 2003James, 2001Smit, 1993a1993bTemplin, 1957). However, some individuals experience difficulties with speech production beyond this age and even into adulthood (Bralley & Stoudt, 1977Felsenfeld, Broen, & McGue, 1992). These children with persistent speech sound disorder (SSD) constitute a substantial proportion (8.8%) of clinical caseloads (Broomfield & Dodd, 2004). This article focuses on those children with clinically significant and persistent SSD that goes beyond the /s/ and /r/ distortions defined by Shriberg (1993)  as common clinical distortions. Using data from a large longitudinal population study, prevalence at age 8 years and associated risk factors are identified to aid our understanding of persistent SSD in the clinical setting.

The final version has just been published but the online version has been available for a couple of months.

It's Open Access and the link to the paper is at

Full citation is Wren, Y., Roulstone, S., Miller, L.L., Emond, A. and Peters, T. (2016) The prevalence, characteristics and risk factors of persistent speech disorder. Journal of Speech, Language and Hearing Research, 59, 647-673.

Further information

For further information please contact Yvonne Wren (

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