Informant-Reported Discrimination, Dementia, and Cognitive Impairment in Older Brazilians.

Abstract

Self-reported discrimination is a source of psychosocial stress that has been previously associated with poor cognitive function in older African Americans without dementia. Here, we examine the association of discrimination with dementia and cognitive impairment in racially diverse older Brazilians. We included 899 participants 65 years or older (34.3% Black) from the Pathology, Alzheimer's and Related Dementias Study (PARDoS), a community-based study of aging and dementia. A structured interview with informants of the deceased was conducted. The interview included the Clinical Dementia Rating (CDR) Scale for the diagnosis of dementia and cognitive impairment proximate to death and the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) as a second measure of cognitive impairment. Informant-reported discrimination was assessed using modified items from the Major and Everyday Discrimination Scales. Discrimination was reported by informants of 182 (20.2%) decedents and was more likely reported by informants of Blacks than Whites (25.3% versus 17.6%, p = 0.006). Using the CDR, a higher level of informant-reported discrimination was associated with higher odds of dementia (OR: 1.24, 95% CI 1.08 -1.42, p = 0.002) and cognitive impairment (OR: 1.21, 95% CI: 1.06 -1.39, p = 0.004). Similar results were observed using the IQCODE (estimate: 0.07, SE: 0.02, p = 0.003). The effects were independent of race, sex, education, socioeconomic status, major depression, neuroticism, or comorbidities. Higher level of informant-reported discrimination was associated with higher odds of dementia and cognitive impairment in racially diverse older Brazilians.