Limitations among adults with arthritis: An analysis of duration, severity, type, and change in severity of arthritis

Arthritis is the most prevalent chronic condition in persons ages 65 and older and is projected to affect 60 million people by 2020 (Dunlop, Manheim, Yelin, Song, and Chang 2003b). For middle and late life, arthritis ranks first for limitations among both women and men (Verbrugge and Patrick 1995). Furthermore, as the population ages, more people will have to live with arthritis for a longer period of time (Leveille, Wee, and Iezzoni 2005). The purpose of this study is to provide an analysis of the impact of duration of arthritis, severity, type, and self-rated change in the severity of arthritis on functional limitations. Many of the activities identified as most important to persons with arthritis are not measured with activities of daily living (ADL) and instrumental activities of daily living (IADL) scales, but with the functional limitations scale, most notably associated with Nagi (1969). Furthermore, duration of disease is largely unstudied. Individuals vary greatly in their adaptation to diseases and this is not always well explained by severity. Duration of disease may affect how one learns to live and function with the disease, therefore increasing one's ability to perform activities. As one lives with chronic disease, one learns to adapt to the challenges of the disease. Alternatively, levels of functional ability may decrease as one lives with the chronic disease because of fear-avoidance and losses in physical functioning as the illness progresses. Using data from the Heath and Retirement Study (HRS), the findings from this study indicate that duration of arthritis is negatively related to functional limitations; functional limitations decrease by 7% for every additional two year period one lives with arthritis. This finding supports the proposition that the longer one lives with arthritis, the more one learns to function and adapt to the disease. Severity of arthritis and self-perceived change in the severity of arthritis are positively related to functional limitations. Functional limitations increase by 15% for every additional unit increase in the severity of arthritis and by 27% when one views their arthritis as worse than during the previous wave. These results demonstrate that not only does severity of arthritis determine how adults with arthritis function, but also that the length of time that one lives with arthritis impacts their functional ability. Examining how various aspects of arthritis impact functional ability may lead to a better understanding of how adults live with chronic health conditions.