Adaptieve Vragenlijst Verstandelijk Beperking De ontwikkeling en psychometrische kwaliteit van het meetinstrument voor adaptief functioneren bij mensen met een licht verstandelijke beperking.

Abstract

Abstract Background In the recently published fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), the diagnosis of intellectual disability is revised from the DSM-IV diagnosis of mental retardation. The most significant change is the way the degree of severity is determined. In de DSM-IV, this diagnosis was based on the Intelligence Quotient (IQ), whereas the in the DSM-V the severity is based on adaptive functioning. This includes the conceptual, social and practical domain. Together, these domains determine how well an individual copes with everyday tasks. The most difficult group to determine the diagnosis for is the one with mild intellectual disabilities. In the Netherlands, no suitable measurement is available fort this group at the moment. Existing instruments are incomplete and outdated. In this context, the researchers of this study developed the Adaptive Questionnaire Intellectual Disability (Adaptieve Vragenlijst Verstandelijke Beperking) to measure adaptive functioning. Furthermore, it was designed for practical use to provide insight in the capabilities and disabilities of an individual. The aim of this pilot study was to investigate whether de AVVB is a reliable and valid instrument for determining adaptive functioning. Methods Participants (N=47) were all inpatients of a clinical ward for people with a mild intellectual disability and mental disorders. Two primary caregivers were asked to complete both the AVVB for inter-rater reliability (IRR) and the SRZ-P, an existing but outdated instrument for self-reliance. The SRZ-P and the IQ-score on the WAIS were used for convergent validity. The ABCL for psychopathology was used for divergent validity. Results The IRR of the scales of the AVVB were all significant and can be reviewed good to excellent (ICC between .66 and .83), the IRR of the total score was significant and excellent (ICC = .81). The same results were found for the internal consistency of the scales (.85 - .94) and the entire test (.98). As expected, we found a fair convergent validity for the SRZ-P (.72) and no significant correlation for the divergent validity. No significant result was found for the WAIS, which was not expected. Conclusions The first results for the psychometric quality indicate that the AVVB might be a reliable and valid instrument to measure adaptive functioning, although they must be interpreted with cautiousness because of the limited sample size. However, these first results are promising for the further development of the AVVB. Moreover, the AVVB is already useful for practical purposes in clinical treatment since it provides insight in the needs of patients.