Psychometric properties of the Social Responsiveness Scale-2 (SRS-2) for Autism Spectrum Disorder

Abstract

Objective: The purpose of this research was to assess the psychometric properties of the Portuguese version of the Social Responsiveness Scale-2 (SRS-2) for children and adolescents with autism spectrum disorder (ASD). Methods: Parents of 90 patients with ASD and 25 healthy controls responded to the SRS-2. Analyses about the discriminant validity, reliability and separation indexes, fitness and items calibration according to Rasch model were carried on. Results: SRS-2 showed good internal consistency (Cronbach’s alpha = 0.952), a cutoff score of 41, sensitivity of 96.8%, specificity of 100%, and negative predictive value of 99.9% for the diagnosis of ASD. The subscales generally fitted the model. However, some items presented suboptimal statistics performance (negative item-total correlation and misfitting). The item map showed that the latent variable was not entirely covered by the items, especially on the mildest end of the autistic spectrum. Conclusion: The results of this study showed that the Portuguese version of SRS-2 can be used as a screening tool to improve the recognition of ASD in Brazilian children and adolescents. The scale might have improved versions in the future with the substitution of items with worse performance.