Alzheimer's disease may contribute to as many deaths in the United States as heart disease or cancer, contrary to numbers reported, according to a new study by researchers at Rush University Medical Center in Chicago.
Currently, the Centers for Disease Control and Prevention show Alzheimer's disease is the sixth leading cause of death in the United States. Heart disease and cancer are numbers one and two, respectively, based on what is reported on death certificates.
“Alzheimer's 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, was quoted as saying." Death certificates often list the immediate cause of death, rather than listing dementia as an underlying cause.”
In the study, 2,566 participants 65 and older received testing for dementia annually. The study found that after an average of eight years 1,090 participants died, and 559 participants without dementia at the start of the study developed Alzheimer's. The average time from diagnosis to death was four years. After death, Alzheimer's disease was confirmed through autopsy for 90-percent of those who were diagnosed. The death rate was four times higher after diagnosis in people 75 to 84 and nearly three times higher in people 85 and older.
James said this translates to 503,400 deaths from Alzheimer's in the US population over age 75, which is six times higher than the 83,000 reported by the CDC based on death certificates.
“From the time of diagnosis to the time of death, the last 40-percent of that time is usually spent in nursing home care,” Dr. Marc Schlosberg, Neurologist at MedStar Washington Hospital Center in Washington, D.C., who is unrelated to the study, told Ivanhoe. “So, all the different complications associated with nursing home care, like urinary tract infections, which can lead to sepsis, ulcers from lying in one place, [and] pneumonia—all are potential complications of Alzheimer's disease. When these patients die, it's not surprising that the death certificate won't list Alzheimer's disease as the primary cause of death…it would list the complication instead.”
Dr. Schlosberg agreed this study points out the vast underestimation of the mortality rate of people in the U.S. with Alzheimer's disease. However, he said another study needs to be done by getting a patient population that may be more representative and more general. For example, Dr. Schlosberg says “Religious [groups] used in determining some of the statistics were made up of priests and nuns,” he said. “In general, those populations are probably more highly educated than the general population, so their rate of Alzheimer's disease, their prevalence, might be lower, [and] it's possible that the cohort could be [an] underestimate.”