ABSTRACT
In the years to come, the U.S. population will include larger numbers of older individuals, likely including the number of people with Parkinson’s disease (PD) and other chronic and degenerative diseases. Demographic studies of PD suggest that the associated changes in functional status and dependency rise dramatically with each year of life.3 Deterioration in functional status in individuals with PD increases the likelihood of their dependence on families, communities, and health care resources. Epidemiological studies suggest that, in diseases such as PD, improving mortality alone leads to a higher prevalence of dependent individuals in the life table population; improving morbidity alone leads to a lower percentage of individuals with problems in functioning, in both the years of life and the proportion of years of dependent life.4
