In 2005, there were approximately 35 million Americans aged 65 years or older constituting 12% of the entire US population, and this percentage is expected to increase to 20% by 2030.1 The ultimate goal for these aging Americans is to increase their probability of aging successfully without cognitive or physical disability. It is estimated that 28.3 million individuals from the 2005 cohort had no functional or cognitive impairment.2,3 However, these healthy older adults have a very high risk for becoming functionally or cognitively disabled over their remaining life span. The probability of their surviving free from disability (active life) until age 85 years ranges from 10% to 37% depending on their sex, educational level, smoking status, and level of physical activity.4 On average, a 65-year-old individual with no cognitive or functional disability has an active life (disability-free) expectancy of 14 years.5 In contrast, a person who survives to age 85 years without disability has an active life expectancy of 4 years.5 Thus, a major challenge facing our aging population is not only reducing overall mortality but actually increasing active life expectancy.
Boustani M, Justiss MD. Subtle Neurological Abnormalities and Functional Cognition in Older Adults. Arch Intern Med. 2008;168(12):1252-1253. doi:10.1001/archinte.168.12.1252