Alzheimer's disease may be an underlying cause of five to six times as many deaths as currently reported, according to a new study. In fact, researchers at Rush University Medical Center, publishing their results in Neurology, say that Alzheimer’s disease may be one of the leading causes of death in the United States.
Data from the Centers for Disease Control and Prevention (CDC), derived from death certificates, indicate that heart disease is the leading cause of death, cancer is number two and Alzheimer's disease ranks sixth.
“The estimates generated by our analysis suggest that deaths from Alzheimer’s disease far exceed the numbers reported by the CDC and those listed on death certificates,” says study author Bryan D. James, PhD, an epidemiologist with the Rush Alzheimer's Disease Center. Death certificates list the immediate cause of death, such as pneumonia, he pointed out, and attempting to identify a single cause of death does not always capture the reality of the process of dying for most elderly people, because multiple health issues often contribute.
The researchers found that the death rate was more than four times higher after a diagnosis of Alzheimer’s in people aged 75 to 84 years and nearly three times higher in people aged 85 years or more. More than one-third of all deaths in those age groups were attributable to Alzheimer’s disease.
The investigators studied 2,566 people aged at least 65 years; participants underwent annual dementia screening. The average time from diagnosis to death was about four years. After death, Alzheimer’s disease was confirmed through autopsy for about 90 percent of those in whom a clinical diagnosis had been made. After an average of eight years, 1,090 participants died. A total of 559 participants without dementia when the study began developed Alzheimer's disease. James says this translates into an estimated 503,400 deaths from Alzheimer’s in the U.S. population over age 75 in 2010, which is five to six times higher than the 83,494 number reported by the CDC based on death certificates.
“Determining the true effects of dementia in this country is important for raising public awareness and identifying research priorities regarding this epidemic,” he says.