Single Word Quick Repetition Test for Speech Sound Production in Farsi Speaking Children: Development, Reliability and Validity

Objective: The aims of the present study was to develop and validate a quick repetition test using familiar, culture-based words for the assessment of the Farsi speaking children suffering from Speech Sound Disorders (SSD). Method: The study population was divided into two groups, including 419 participants without any clinical signs of speech impairment and 36 cases with SSD. Psychometric properties of single word quick repetition test including reliability (inter-rater and test retest reliability) and validity (construct –discriminant and convergent validity-, clinical and concurrent validity) were examined. Also, descriptive data for children without SSD were reported. Results: Test-retest and inter-rater reliability were satisfactory (ICC > 0.7). The correlation between the results of the quick repetition test and phonetic test demonstrated a positive correlation indicating acceptable convergence validity. Using inflated beta-binomial regression, statistically significant improvement in test score with age was found (discriminant validity). Comparison of the correct responses of the control and case groups (clinical validity) showed that there is a significant difference between responses of these two groups of children. Results of Bland–Altman plot showed an acceptable agreement between quick repetition test and phonetic test (construct validity). Discussion: Farsi quick repetition test is a reliable and valid instrument facilitating the screening of speech sound abilities in children within the age group of 3-8 years. Moreover, the shortness of this test makes it easily applicable in clinical practice and epidemiologic investigations. The establishment of descriptive data from a large sample facilitated the comparison of child speech ability with the speech development standards.