Validation of the Mild Behavioral Impairment Scale (MBI-S) for brief self-assessment of Mild Behavioral Impairment in people without dementia.

Abstract

Background: Mild Cognitive Impairment (MCI) and Mild Behavioral Impairment (MBI) are important constructs in the context of cognitive decline. MBI can be assessed with the Mild Behavioral Impairment Checklist (MBI-C). However, the instrument has deficits in psychometrics and content, thus indicating a need for improvement. The aim of this study was to develop a complementary short instrument, the Mild Behavioral Impairment Scale (MBI-S), designed to measure MBI as a short-term modifiable state criterion, and to validate it in a non-clinical sample of people 18 years of age or older.

Methods: Most of the items on the MBI-S stem from the MBI-C and were chosen to represent the dimensions of the Neuropsychiatric Inventory Questionnaire. The MBI-S was validated on self-reported data from 175 individuals. In an item analysis, the discriminatory power and item difficulties were examined. Cronbach's alpha was calculated to assess the internal consistency, and a principal component analysis was conducted to determine the structure of the instrument. Construct validity was established by testing four hypotheses about relationships between the MBI-S and other instruments by calculating correlation coefficients.

Results: After the item analysis, two items were removed from the final version of the scale on the basis of insufficient discriminatory power and the finding that the internal consistency of the total score increased when the items were deleted. The principal component analysis yielded a single-component structure for the MBI-S. Two more items were excluded from the scale due to insufficiently low loadings on the extracted component. Cronbach's alpha for the final eight-item scale was 0.79. The final MBI-S score was strongly related to that of the MBI-C and a loneliness score as well as moderately related to maladaptive coping. There was no association with respondents' level of education.

Conclusion: The MBI-S is a valid short instrument for the assessment of MBI. It has high test economy and measures current neuropsychiatric symptoms and their intensity as a state criterion. Therefore, the MBI-S can be used for the longitudinal measurement of MBI.