Psychometric evaluation of a Dutch version of the Mini PAS-ADD for assessing psychiatric disorders in adults with different levels of intellectual disability

Abstract

Background: People with intellectual disabilities (ID) have an increased vulnerability to develop psychiatric problems. Moreover, the early recognition and the accurate diagnosis of psychiatric disorders in the population of persons with ID are challenging.

Method: A Dutch version of the Mini PAS-ADD, which is a screening instrument for identification of mental health problems in people with ID, was evaluated in terms of internal consistency, interinformant reliability, item grouping and criterion validity based on a large-scale random sample (n = 377) and a clinical sample (n = 99) of adults with ID.

Results: The Dutch version of the Mini PAS-ADD showed moderate internal consistency, and moderate concordance among informants. Both aspects of the reliability were comparable for different levels of ID. A factor analysis largely confirmed the scale structure. Concurrent validity with the Reiss Screen for Maladaptive Behavior was high for the Depression, Psychosis and Autism scale. The outcome of the criterion-validity analysis indicated high specificity. The sensitivity for specific psychiatric disorders by the corresponding scales was moderate, but the general sensitivity for the presence of psychopathology on the basis of any of the scales was satisfying.

Conclusions: The present research reconfirmed the use of the Mini PAS-ADD as a primary screening device for the identification of mental health problems among people with ID.

Keywords: behavioural measurement methods; intellectual disability; mental health; psychiatric disorders.