INTRODUCTION: Autism spectrum disorder (ASD) in adults is exhibiting an increase in prevalence, and a growing rate of referrals is observed from primary health professionals to specialised units. The heterogeneous clinical presentation and high prevalence of comorbidity seen in ASD challenges the case identification, emphasising the need for screening tools with a high validity and reliability. Previously, satisfactory psychometric properties of the Ritvo Autism Asperger Diagnostic Scale - Revised (RAADS-R) have been demonstrated, and it is a widely used screening tool in Denmark. Nevertheless, a validation of a Danish version of the RAADS-R has not been performed in a Danish population. To evaluate its clinical relevance, we aim to test the psychometric properties of a Danish translation of the RAADS-R (RAADS-R-DK) in an adult population.

METHODS: We aim to test 200 ASD patients, 200 non-ASD psychiatric patients and 200 healthy controls. The results from the RAADS-R will be compared with the clinical diagnoses from interdisciplinary teams at specialised outpatient clinics.

CONCLUSION: The aim of the study is to investigate the validity, reliability and clinical features of the RAADS-R-DK.

FUNDING: Mental Health Center, TrygFonden, Sofiefonden and Takeda Pharma.

CLINICALTRIALS: gov NCT05213286.