Contrary to official statistics, Alzheimers disease may contribute to almost as many deaths in the U.S. as heart disease or cancer, according to a study.
Alzheimers disease falls sixth on the list of leading causes of death in the U.S., according to the CDC, with heart disease and cancer ranking first and second. These numbers are based on what is reported on death certificates, according to background information in the study, which was published in the March 5 issue of the journal Neurology.
However, Alzheimers disease and other dementias are under-reported on death certificates and medical records, study author Bryan D. James, PhD, of Rush University Medical Center in Chicago, said in a news release. Death certificates often list the immediate cause of death, such as pneumonia, rather than listing dementia as an underlying cause.
James added that attempting to identify a single cause of death does not always capture the reality of the process of dying for most elderly people, who in many cases have multiple contributing health issues.
The estimates generated by our analysis suggest that deaths from Alzheimers disease far exceed the numbers reported by the CDC and those listed on death certificates, James said.
For the study, 2,566 people ages 65 and older received annual testing for dementia. The average age of the participants was 78.
The researchers found that after an average of eight years, 1,090 participants died. A total of 559 participants without dementia at the start of the study developed Alzheimers disease, with an average time from diagnosis to death of about four years. After death, Alzheimers disease was confirmed through autopsy for about 90% of those who were clinically diagnosed.
The death rate was more than four times higher after a diagnosis of Alzheimers in people ages 75 to 84 and nearly three times higher in people ages 85 and older. Based on their statistical analysis, the researchers concluded that more than a third of all deaths in those age groups were attributable to Alzheimers disease.
James said this rate translates into an estimated 503,400 deaths from Alzheimers 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. By comparison, 598,000 deaths were attributable to heart disease and 575,000 to cancer.
Determining the true effects of dementia in this country is important for raising public awareness and identifying research priorities regarding this epidemic, James said.
Neurology is the medical journal of the American Academy of Neurology. Study abstract: http://bit.ly/1icXTEM