Psychometric Properties of the Social Responsiveness Scale 2nd Edition (SRS-2) and Development of a Short Version in a Spanish Sample.

Earlier identification of autistic traits is crucial for timely interventions in children and adolescents. This study aims to evaluate the psychometric properties of the Social Responsiveness Scale 2nd Edition (SRS-2) -answered by parents- in a Spanish population and to develop a shortened form of the scale for autism screening. A total of 528 children and adolescents with autistic diagnosis, ADHD, and non-diagnosis participated in the study. Factorial analysis indicated a unidimensional structure with excellent reliability (Cronbach's α = .96) and a KMO index of .95. A moderate sensitivity (69.4%) and high specificity (88.5%) were found for a score of ≥ 60. The 10 items with the highest factor loading have constituted a reliable SRS-2 short form (α = .92), valid for identifying autism. This shortened version showed an area under the ROC curve of 86.3%, with high sensitivity (83.8%) and moderate specificity (75.3%) for a score of ≥ 5. This short form has shown to be an effective screening tool in the Spanish population, retaining psychometric properties comparable to the original scale. The findings conclude that both versions are reliable and valid, and we support the utility of the SRS-2 short form as a practical tool for improving autism detection in the Spanish population, with significant implications for clinical and research applications.