Psychometric Properties of the MacArthur-Bates Communicative Development Inventories-III (CDI-III) in 30 to 37 Months Old Persian-Speaking Children

Objective:

 Early language skills predict the child’s future language skills and literacy. So, screening and assessment of speech and language at an early age are important. One cost-effective way of assessing a child’s communication is through parents reporting tools. MacArthur-Bates Communicative Development Inventories (CDIs) are the most widely used forms by professionals in more than 70 live languages worldwide to screen children’s communication skills. The main purpose of this study was to provide the Persian version of the third form of CDI (CDI-III) and determine its psychometric properties, including face and content validity and internal consistency in 30 to 37 months old Iranian Persian-speaking children.

Materials & Methods:

 In a cross-sectional methodological study of instrument validation, a Persian-adapted form of CDI-III was developed. At first, the English form was adapted to Persian, and a Delphi method was used to provide the initial list of the items. The face and content validity rates were examined by asking the opinion of ten Persian-speaking speech and language pathologists with at least three years of clinical experience in the field of child speech/language development and disorders. The final form was compiled based on the results of the content validity ratio (CVR) and content validity index (CVI) of the items. The final form consisted of three sections, including vocabulary, sentences, and use of sentences. The parents of 356 Persian-speaking children aged 30 to 37 months recruited by multi-stage cluster random sampling from health centers in Isfahan City were asked to complete the form. The Kuder-Richardson coefficient assessed internal consistency, and the Spearman coefficient examined correlation.

Results:

 The items with CVIs≥0.7 and CVRs≥0.6 remained, and other items were reviewed or removed based on the suggestions of panelists and developers. The final form included 100 words, 22 pairs of sentences, and 16 questions about using sentences. A total of 356 children (mean±SD age: 34.03±2.12 months) were included in the study. According to the English CDI-III guidelines, the data were divided into four age groups with two-month intervals: 30-31, 32-33, 34-35, and 36-37. The internal consistency of the whole form was 0.97, and internal consistency values of vocabulary, sentences, and sentence usage were calculated as 0.98, 0.88, and 0.88, respectively. The Spearman correlation values between the scores of the form sections and each section with age indicated a significant positive correlation between all sections of the form. Also, the significant positive correlation between age and all three parts showed that the number of expressive words, the grammatical complexity of sentences, and the proper use of sentences increase with age.

Conclusion:

 The Persian CDI-III form possesses a good face and content validity and internal consistency to be used as a valid tool for screening language competence of 30-37 months old Persian-speaking children. The results of the mean and standard deviation of the current study can be used as a comparison for screening children suspected of being language deficient.