Posted on Aug 21, 2012, 6 a.m.
Rush University (US) researcher reports that nearly 500,000 deaths in 2007 are attributable to the condition, factoring in chronic coexisting conditions that leave people weak and fragile and thereby lead to death.
While the US Centers for Disease Control & Prevention (CDC) filed vital statistics for 2008 listing official number for deaths from Alzheimer's disease at 82,000, Bryan James, from Rush University (Illinois, USA), and colleagues contend that the CDC statistics were based on death certificates, and fail to factor in chronic coexisting conditions that leave people weak and fragile and thereby lead to death. The team analyzed data collected in the Religious Orders Study (began in 2004) and the Rush Memory and Aging Project (began in 1997), the total of both following 2,500 older men and women with cognitive tests and other exams. Autopsy data were available for more than 80% of the approximately 1,000 participants who have died so far. Deaths among participants who developed incident Alzheimer's disease during follow-up were far more common than in those remaining dementia-free: of 516 who developed Alzheimer's disease, 68.0% died, compared with 32.3% of those without incident Alzheimer's. Median time to death for participants who developed Alzheimer's disease was 2.7 years. The data from the two Rush cohorts were then extrapolated to the entire US population, using vital statistics data from 2007. Careful to distinguish deaths with Alzheimer's disease and deaths from the disease, the team estimates that 477,800 deaths in 2007 could be attributable to Alzheimer's disease. Noting that reduction of the frequency of diagnostic assessments leads to underestimates of the attributable risk, the study authors submit that deaths from Alzheimer's disease may be six times more common than official statistics indicate.
James B, et al. "Attributable risk of mortality from incident Alzheimer's disease" [Abstract P2-174]. Presented at Alzheimer's Association International Conference, 20 July 2012.