Psychometric evaluation of the Italian version of the AADS questionnaire: a caregiver-rated tool for the assessment of behavioral deficits and excesses in persons with intellectual disabilities and dementia.

<bold>Background: </bold>The aim of this study was to verify the reliability and validity of the Italian version of the Assessment for Adults with Developmental Disabilities (AADS-I), the only available measure specifically designed to assess the frequency, management difficulties and impact on the quality of life (QoL) of positive and negative non-cognitive symptoms in persons with intellectual disabilities (ID) and dementia.<bold>Methods: </bold>AADS-I was administered to professional carers of 63 aging ID individuals. We computed the internal consistency separately of the frequency, management difficulty and effect on the QoL subscales of Behavioral Excesses and Behavioral Deficits and their inter-rater and test-retest reliabilities.<bold>Results: </bold>Homogeneity of AADS-I was found to range from good to excellent: Cronbach's α coefficients were 0.77, 0.83 and 0.82, respectively for frequency, management difficulty and effect on the QoL of Behavioral Excesses, and 0.82, 0.76 and 0.79 of Behavioral Deficits. Intraclass correlation coefficients (ICC) between two independent carers were 0.67, 0.79 and 0.73 and 0.67, 0.67 and 0.67 for frequency, management difficulty and effect on the QoL of Behavioral Excesses and Deficits, respectively. Corresponding ICC for test-retest reliability were 0.80, 0.75, 0.78 and 0.70, 0.81, 0.81. Age, gender and typology of ID did not correlate with the AADS-I subscale scores, whereas the severity of ID related only with the frequency subscale of Behavioral Deficits. This subscale also correlated with the Dementia Questionnaire for Persons with Intellectual Disabilities. Behavioral deficits are more frequent in subjects with dementia.<bold>Conclusions: </bold>These results confirm the reliability and validity of the Italian version of AADS. [ABSTRACT FROM AUTHOR]