Autor:innen:
J. Rausch (Freiburg im Breisgau, DE)
T. Fangmeier (Freiburg im Breisgau, DE)
C. Falter-Wagner (Freiburg im Breisgau, DE)
J. Espelöer (DE)
H. Ackermann (Freiburg im Breisgau, DE)
L. Hölzel (Freiburg im Breisgau, DE)
A. Riedel (Freiburg im Breisgau, DE)
R. Ritvo-Slifka (Freiburg im Breisgau, US)
K. Vogeley (Freiburg im Breisgau, DE)
L. Tebartz van Elst (Freiburg im Breisgau, DE)
Background
The Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R) has shown to produce very good results in its original study with a sensitiviy of 97% and a specificity of 100%. It was therefore included in the National Institute for Health and Care Excellence (NICE) guidelines. The questionnaire includes 80 questions on four subcategories (language, social relatedness, circumscribed interests, sensory motor). So far, the subcategory sensory motor has not been subject to questionnaires, although it refers to a diagnostic criterion of the diagnosis of autism in DSM-5 and ICD-11.
Methods
In our validation study we tested the translated version of the questionnaire on 299 individuals (110 persons with ASD, 64 persons with axis I disorder, 125 persons with no disorder). To improve the practicablity of the instrument in clinical reality, in difference to the original study, the questionnaire was filled in by the test subjects only without the presence of a clinician. Psychiatric diagnoses had been established following highest standards and psychometric properties were calculated following established protocols
Results
The German version of the RAADS-R produced very good results with a high sensitivity of 92.5% and a high specificity of 93.5%. The area under the curve was very large (AUC = 0.976) and indicates a high quality and discriminatory power of RAADS-R. Furthermore, the ROC curve analysis shown, that the best threshold to distinguish between the ASD and non-ASD groups in the German version of the RAADS-R is a score of 81. In comparison to the RAADS-R in this sample the co-administered instruments Social Responsiveness Scale (SRS), Autism Spectrum Quotient (AQ) and Empathy Quotient (EQ) individually all yielded a slightly better specificity but worse sensitivity.
Conclusion
The RAADS-R compares well to other screening instruments and is capable of providing valuable additional information. Therefore, it could turn out to be a helpful diagnostic instrument.