Assessing cognitive impairment in an ethnically diverse cohort of oldest-old: the life after 90 study.

Background: Though dementia rates vary by racial or ethnic groups, it is unknown if these disparities remain among those aged 90 or older.

Aims: To test this hypothesis, we used baseline clinical evaluation of 541 ethnically and racially diverse individuals participating in the LifeAfter90 Study to assess how associations between core demographic characteristics and measures of physical and cognitive performance differ across the racial/ethnic groups.

Methods: Participants in this study were long-term non-demented members of Kaiser Permanente Northern California.