Evaluation of the psychometric indicators of the Comprehensive Autistic Trait Inventory in Iranian adults

Background: The DSM-5's Comprehensive Autism Traits Inventory (CATI) was a useful diagnostic tool for the general population because it covered all the critical aspects of autism. However, its reliability and validity in the overall Iranian population still need to be investigated. Purpose: We reviewed the inventory and estimated the validity and reliability of the Iranian version of CATI among 1800 adults. Methods: The Persian version of CATI (CATI-I) was administered to 1800 Iranian adults using the online Star Questionnaire system. Internal consistency, convergent validity, discriminant validity, test-retest reliability, and measurement invariance across genders were calculated. Results: The Correlated social & non-social bifactor model showed the best fit in the Iranian community (CFI=.966; TLI=.947; RMSEA=.045; SRMR=.028). Ultimately, the CATI-I scale in the Iranian community consisted of 39 items across six factors and two higher-order constructs. Additionally, the CATI-I scale's convergent validity and reliability values were acceptable. Conclusion: The CATI-I demonstrates satisfactory reliability and validity in measuring autism traits. It is an appropriate model for the second-order social and non-social factors, and it also shows measurement invariance across genders.