for technological change—for instance, individuals who previously were considered to have IADL disability because they could not shop or pay bills can now do these things online—and are more sensitive to the impact of the environment on functional capacity, including factors that restrict participation in activities. There has been interest as well in measuring a broader range of functional ability. Accordingly, a set of new self-reported measures has been developed and validated and will first be deployed in the emerging National Health and Aging Trends Study (Freedman et al., 2011). In addition, the Census Bureau’s Survey of Income and Program Participation has recently updated its module on disability, adding new measures related to communication, ability to function independently, and a variety of measures of physical functioning.
With respect to disease states, depression is by far the most common mental disorder that influences work and home life. Over 4 percent of Americans are estimated to suffer clinically significant depression during their life, with the disorder being twice as common in women as in men and peaking in prevalence in the 25–44 year age group (Elinson et al., 2004).
With some exceptions, analyses of functional status in community-based populations have relied on one or more of the following five nationally representative longitudinal survey-based datasets: