Reliability and Validity of the Cornell Scale for Depression in Dementia and Invariance Between Black Versus White Residents in Nursing Homes

Abstract

Objectives: The purpose of this study was to expand on prior work testing invariance on several depression measures in community-based older adults and explore the psychometric properties and evidence of invariance between racial groups based on the Cornell Scale for Depression in Dementia.

Design: This was a descriptive measurement study.

Setting and participants: This was a secondary data analysis using baseline data from 2 studies: Testing the Implementation of the Evidence Integration Triangle for Behavioral and Psychological Symptoms Associated with Dementia and the study Testing the Impact of Function and Behavior Focused Care for Nursing Home Residents with Dementia. Combined, 67 nursing homes participated from 2 states and 889 residents were recruited. The mean age of the participants was 86.58 (SD 10.31) and most were women (72%) and White (70%).

Methods: This was a descriptive study, and a Rasch analysis was done to establish reliability based on internal consistency and evidence of differential item functioning (DIF) across races. Validity was based on item fit and model testing with structural equation modeling to compare models between White and Black participants.

Results: There was evidence of internal consistency (alpha coefficient of 0.98) and no significant evidence of DIF. The item related to suicide had a high logit and did not significantly load onto the measurement model for Black individuals. There was not a good spread of the items across the concept of depression. The model had a better fit with the items when used with White versus Black participants.

Conclusions and implications: The findings indicate that it would be helpful to add some additional items that reflect depressive symptoms among this population. Further, the findings serve as a reminder that this measure may be biased toward identification of symptoms of depression among White versus Black residents.

Keywords: Dementia; depression; disparities; measurement; nursing homes.