To, C. K-S., Cheung, K. Y., Law, T., Lee, K. Y. S., McLeod, S., & Ng, M. L. (2014-2015). 利用存活分析調查構音問題的自然史 – 預後及誘發因素的研究 [Investigating prognosis and risk factors of speech sound disorder: A natural history study using a survival analysis approach]. General Research Fund, Research Grants Council (RGC) of Hong Kong, China (GRF 17409214).
Here is the abstract:
Speech sound disorder (SSD) is a prevalent childhood communication disorder and forms a significant caseload of speech-and-language-therapy services in Hong Kong (To, Law & Cheung, 2012). SSD in preschool children can be persistent and may lead to long-term literacy difficulties. Emerging evidence indicates possible speech processing deficits that underlie SSD and later reading disorder. At the other end of the spectrum, a sizable subgroup of children originally demonstrates speech problems outgrow their speech errors without clinical attention and follow the typical growth trajectory in later years. Previous studies using simple correlation and the logistic regression have successfully identified risk factors that are significantly associated with the occurrence of SSD. However, these studies did not include time aspect and did not address the speech processing problems which can explicate different presentations of SSD, i.e., transient and persisting SSDs. Given the large variability in the growth trajectory of speech development and its disorder, previous studies may not provide much strong evidence on prognosis. This current study will employ a research technique of the survival analysis with the use of Cox's regression model to investigate the evolution of speech sound development along with children’s speech processing ability in those with SSD. The statistical analysis method is particularly for longitudinal designs and has taken into account the major problem of subject drop due to lost to follow up. We recruit Cantonese-speaking preschoolers who demonstrate the concern of speech problems without other known developmental problems in Hong Kong. To achieve adequate statistical power for analysis, 76 preschoolers with SSD aged at 5 years old will be recruited at the baseline using a validated parental questionnaire. Children who fit the inclusion criteria will be reassessed at a 6-month interval for a period of 2 years or until they master their sound inventory. Besides the child-related and family risk factors, the child’s speech processing ability will also be investigated in the present study. At the theoretical level, the findings result from the present study on the speech processing ability may dissect possible points of processing constraint in children with persisting SSD. At a clinical level, such a predictive model can contribute towards the evidence for speech-language therapists (SLTs) to better predict outcomes and estimate prognosis for children with SSD, and to decide on the appropriate treatment options. This will eventually lead to improved clinical estimation of prognosis SSD and better allocation of resources to early intervention provision.