Alzheimer's disease and milder forms of dementia are associated with an increased risk of death but the risks are the same for both black and white people. Some studies have found that African Americans live longer after being diagnosed with the condition than white people but a study of 1715 older adults by researchers at the Rush University Medical Center in Chicago found no differences between racial groups. At the start of the study 802 participants had no cognitive problems, 597 had mild impairment, 296 had Alzheimer's disease and 20 had other forms of dementia. Over the 10 years of the study 634 of the participants died. Compared to unaffected people the risk of death was around 50% higher in people with mild cognitive impairment and 200% higher in those with Alzheimer's.