Screening for Anxiety in People with an Intellectual Disability: German Version of the "Glasgow Anxiety Scale for People with an Intellectual Disability" (GAS-ID)

Abstract

As of yet, there exists no German-language self-rating questionnaire as a screening for anxiety disorders in people with an intellectual disability. Therefore the Glasgow Anxiety Scale for people with an Intellectual Disability (GAS-ID) was translated into German and its psychometric properties were assessed. Internal consistency and concurrent validity were tested in 34 adults with learning difficulties and mild and moderate intellectual disability. Convergent validity was estimated by using data from a clinical sample of 38 persons without intellectual disability. The GAS-ID discriminates between intellectually disabled subjects with an anxiety disorder and subjects without comorbid mental disorders resulting in a sensitivity of 100 % and a specificity of 87 %. It also demonstrates a very good internal consistency (Cronbachs α = 0.90) and a high convergent validity (with BAI: r = 0.76). The German GAS-ID is a reliable, valid and economically applicable self-report screening instrument for assessing anxiety in people with intellectual disability. However, minor revision of items and future research is needed to investigate the validity of the GAS-ID.