Adaptation and validation of intelligibility in context scale as a screening tool for Hong Kong preschoolers

Abstract

Intelligibility in Context Scale (ICS) is a parent report questionnaire developed based on the Environmental and Personal domain of the International Classification of Functioning, Disability and Health — Children and Youth Version (ICF-CY) (World Health Organization, 2007) for assessing children's speech intelligibility (McLeod, Harrison, & McCormack, 2012). This study aimed to adapt ICS into Chinese, namely, ICS-C, and examine the psychometric properties of the adapted version when applying to Cantonese-speaking children. A secondary objective was to identify speech measures ICS-C was sensitive to. A total of 72 Cantonese-speaking preschoolers with (N = 39) and without speech sound disorders (SSD) (N = 33) were recruited. Native Cantonese-speaking parents completed ICS-C independently. Results demonstrated good internal consistency and test-retest reliability of ICS-C. Correlations with speech performance, and significant difference in ICS-C mean scores between the two groups supported validity of ICS-C. The optimal cutoff was estimated using Receiver Operative Characteristic (ROC) curve analysis, giving a sensitivity of .70 and specificity of .59. ICS-C mean scores showed positive correlation with PICC and negative correlation with frequency of atypical errors, both were moderate in strength. Given the satisfactory psychometric properties of ICS-C, it can be a valuable clinical tool for screening of SSD in preschoolers.