Project Description

A population study of prevalence, severity, impact and service provision

An Australian Research Council Discovery Project (DP0773978)

Communication disorders may encompass difficulties in the areas of language, voice, fluency and speech.  A recent Australian study found that the prevalence of communication disorders among 14,500 school aged children may be as high as 13% (McLeod & McKinnon, 2007).  As an area of learning need, communication disorders were found to be more prevalent than behavioural/emotional difficulties, physical/medical disabilities, and intellectual disabilities.

The prevalence of communication disorders, and particularly speech impairments (SI), in Australian preschool children is unclear. Speech refers to the production of sounds, and children with difficulties in this area traditionally comprise a large percentage of speech-language pathologists’ caseloads. While there have been multiple studies investigating prevalence rates (Law,  Boyle, Harris, Harkness & Nye, 2000),  comparisons between studies are difficult due to differences in study design, including means of identifying children with SI (Blum-Harasty & Rosenthal, 1992).  Yet accurate prevalence information is important for planning and evaluating service delivery (Law et al., 2000).

The Principal Investigators have received funding from the Australian Research Council to investigate the prevalence, severity, impact and service provision for Australian preschool children with SI.  Phase 1 of the project will utilise data from the Longitudinal Study of Australian Children (LSAC), which is investigating the development, and factors that influence development, of approximately 10,000 infants and young children in Australia.  Specifically, longitudinal data from this study will be used to:

  1. Indicate the prevalence of children with SI in the Australian population in the early childhood years, and identify risk factors associated with prevalence rates
  2. Examine the impact of having a SI on children’s social, behavioural and academic development
  3. Examine education and health policies regarding service provision for children with SI and compare these with families’ reported experience of accessing and using these services

In addition, phases 2 - 4 will be conducted using a non-clinical sample of children with SI.  This smaller study will add detailed information to extend the findings from the LSAC project.  Specifically, the aims of this smaller project will be to:

  1. Describe the severity of impairment of children identified by parents and/or teachers as having SI (through direct assessment of speech functioning)
  2. Examine the impact of having a SI on children’s development and well-being, and on families’ well-being
  3. Describe families’ experience of service provision including barriers and facilitators to access and use

A communication impairment can impact on a child’s entire life (Felsenfeld, Broen & McGue, 1994). Intervention for children with SI has been found to be effective, particularly when conducted prior to school entry (Almost & Rosenbaum, 1998).  However, not all families have access to necessary services (O’Callaghan, McAllister & Wilson, 2003).  By combining data from both the LSAC project (phase 1) and phases 2 - 4, this project will be able to provide recommendations regarding the needs of children with SI to health and education sectors throughout Australia – to reduce the number of unmet needs through improved access to services and to ensure a holistic model of intervention is provided to these children.


Almost, D. & Rosenbaum, P. (1998). Effectiveness of speech intervention for phonological disorders: A randomized controlled trial. Developmental Medicine and Child Neurology, 40, 319-325.
Blum-Harasty, J. A., & Rosenthal, J. B. M. (1992). The prevalence of communication disorders in children: A summary and critical review. Australian Journal of Human Communication Disorders, 20, 63-80.
Felsenfeld, S., Broen, P. A., & McGue, M. (1994). A 28-year follow up of adults with a history of moderate phonological disorder: Educational and occupational results. Journal of Speech and Hearing Research, 37, 1341-1353.
Law, J., Boyle, J., Harris, F., Harkness, A., & Nye, C. (2000). Prevalence and natural history of primary speech and language delay: Findings from a systematic review of the literature. International Journal of Language & Communication Disorders, 35(2), 165-88.
McLeod, S., & McKinnon, D. H. (2007). The prevalence of communication disorders compared with other learning needs in 14,500 primary and secondary school students. International Journal of Language and Communication Disorders, 42(S1), 37-59.
O’Callaghan, A. M., McAllister, L. & Wilson, L. (2005) Barriers to accessing rural paediatric speech pathology services: Health care consumers’ perspectives. Australian Journal of Rural Health, 13(3), 162-171.