Race/ethnic differences in AD survival in US Alzheimer's Disease Centers

OBJECTIVE: Survival after Alzheimer disease (AD) is poorly understood for patients of diverse race/ethnic groups. We examined whether nonwhite AD patients (African American, Latino, Asian, American Indian) had different rates of survival compared with white AD patients. METHODS: The National Alzheimer's Coordinating Center (NACC) cataloged data from more than 30 Alzheimer's Disease Centers in the United States from 1984 to 2005. Patients aged 65 years or older with a diagnosis of possible/probable AD were included (n = 30,916). Survival was calculated using Cox proportional hazards models with a primary outcome of time to death. Secondary outcomes of this study were neuropathologic characteristics on an autopsied subsample (n = 3,017). RESULTS: The 30,916 AD patients in the NACC were followed up for 2.4 +/- 2.9 years (mean age 77.6 +/- 6.5 years; 65% women; 19% nonwhite 12% African American, 4% Latino, 1.5% Asian, 0.5% American Indian, and 1% other). Median survival was 4.8 years. African American and Latino AD patients had a lower adjusted hazard for mortality compared with white AD patients (African American hazard ratio HR 0.85, 95% CI 0.74 to 0.96; Latino HR 0.57, 95% CI 0.46 to 0.69). Asians and American Indians had similar adjusted hazards for mortality compared with white AD patients (p > 0.10 for both). African American and Latino autopsied AD patients had similar neuropathologic characteristics compared with white AD patients with similar clinical severity. CONCLUSIONS: African American and Latino Alzheimer disease (AD) patients may have longer survival compared with white AD patients. Neuropathology findings did not explain survival differences by race. Determining the underlying factors behind survival differences may lead to longer survival for AD patients of all race/ethnic backgrounds.