A - 128 Informant Characteristics Impact Clinical Dementia Rating Scale Sum of Boxes in Mild Cognitive Impairment

Abstract Objective The Clinical Dementia Rating (CDR) Scale is an informant-based instrument widely used in clinical and research settings to stage dementia severity. Informant-based reports of functioning have been shown to be influenced by informant characteristics, indicating a potential source of bias. The current study adds to this growing area of research by exploring the differential impact of informant characteristics on CDR Sum of Boxes (CDR-SB) among non-Hispanic White (NHW), non-Hispanic Black (NHB) and Hispanic older adults with mild cognitive impairment (MCI). Method Participants included 2775 older adults diagnosed with MCI from the National Alzheimer’s Coordinating Center Uniform Data Set. Multiple linear regression models with forward selection evaluated the extent to which various informant characteristics predicted CDR-SB scores in the whole sample and NHW (n = 2170), NHB (n = 495), and Hispanic (n = 110) groups, covarying for participant demographics and cognition (MoCA). Results Informant sex, education, age, relationship type, and cohabitation status significantly predicted CDR-SB scores in this sample (R2 = 0.096, p < 0.001). Models stratified by race and ethnicity accounted for 20.2%, 10.3%, and 6.9% of the variance in CDR-SB scores in Hispanic, NHB, and NHW groups, respectively (ps < 0.001). Variability in model predictors was observed across groups, with informant characteristics accounting for more model variance than participant demographics in Hispanic and NHB groups. Results remained significant after adjusting for multiple comparisons. Conclusions Informant characteristics and relational factors may influence perceptions of participant functioning on the CDR-SB and may particularly affect scores among Hispanic older adults with MCI, though further validation in community-based cohorts with adequate racial and ethnic representation is warranted.