Cognitive impairment in racially/ethnically diverse older adults: Accounting for sources of diagnostic bias
Dan Mungas, Crystal Shaw, Eleanor Hayes‐Larson, Charles DeCarli, Sarah Tomaszewski Farias, John Olichney, Hector Hernandez Saucedo, Paola Gilsanz, M. Maria Glymour, Rachel A. Whitmer, Elizabeth Rose Mayeda
Abstract
INTRODUCTION: The Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study enrolled Asian, Black, Latino, and White adults ages 65+ without prior dementia diagnosis (N = 1709). We evaluated the prevalence of cognitive impairment (mild cognitive impairment or dementia) accounting for potential biases. METHODS: A random subgroup (N = 541) received clinical evaluation and others were evaluated if they failed a cognitive screen. Diagnoses were made under two conditions: (1) demographics-blind, based on clinical exam and demographically adjusted neuropsychological test scores; and (2) all available information (clinical exam, demographics, and adjusted and unadjusted test scores). RESULTS: Cognitive impairment prevalence was 28% for blinded-adjusted diagnosis and 25% using all available information. Black participants had higher impairment rates than White (both conditions) and Latino (blinded-adjusted diagnosis) participants. Incomplete assessments negatively biased prevalence estimates for White participants. DISCUSSION: Racial/ethnic disparities in cognitive impairment were amplified by attrition bias in White participants but were unaffected by type of test norms and diagnosticians' knowledge of demographics.