In the new study, the Gavrilovs examined a U.S. Social Security database of birth dates and death dates of more than 9 million people born between 1875 and 1895.
The study authors found that the risk of death each year didn't stop rising at the same rate after age 80, as was previously believed. They said the death rate continued to rise at about the same rate up until age 106.
The findings suggest that people over the age of 80 may not have as many years as they might assume, Gavrilov said. For this reason, "we need to be more proactive and support ways to delay aging and extend healthy life span," he said.
Lynch said the research makes sense. However, he added, "I'm hesitant to say that 50 years of theory and studies have been wrong on the basis of one study."
The research, published online Feb. 13 in the North American Actuarial Journal, was funded by the U.S. National Institute on Aging. The Gavrilovs are expected to present their findings at the annual meeting of the Chicago Actuarial Association on March 13.
Recently, the U.S. Census Bureau had to revise estimates regarding the number of centenarians living in the United States. In 2005, it predicted that by 2010 there would be 114,000 people over 100, but the real total was less than half that, it found.
The U.S. National Library of Medicine has more about healthy aging.
SOURCES: Leonid Gavrilov, Ph.D., research associate, Center on Aging, University of Chicago; Scott M. Lynch, Ph.D., associate professor, department of sociology and office of population research, Princeton University, Princeton, N.J.; Feb. 13, 2012, North American Actuarial Journal, online
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