Effect of arthritis in middle age on older-age functioning.

OBJECTIVES To examine whether symptomatic arthritis in middle age predicts the earlier onset of functional difficulties (difficulty with activities of daily living (ADLs) and walking) that are associated with loss of independence in older persons. DESIGN Prospective longitudinal study. SETTING The Health and Retirement Study, a nationally representative sample of persons aged 50 to 62 at baseline who were followed for 10 years. PARTICIPANTS Seven thousand five hundred forty-three subjects with no difficulty in mobility or ADL function at baseline. MEASUREMENTS Arthritis was measured at baseline according to self-report. The primary outcome was time to persistent difficulty in one of five ADLs or mobility (walking several blocks or up a flight of stairs). Difficulty with ADLs or mobility was assessed according to subject interview every 2 years. Analyses were adjusted for other comorbid conditions, body mass index, exercise, and demographic characteristics. RESULTS Twenty-nine percent of subjects reported arthritis at baseline. Subjects with arthritis were more likely to develop persistent difficulty in mobility or ADL function over 10 years of follow-up (34% vs 18%, adjusted hazard ratio (HR)=1.63, 95% confidence interval (CI)=1.43-1.86). When each component of the primary outcome was assessed separately, arthritis was also associated with persistent difficulty in mobility (30% vs 16%, adjusted HR=1.55, 95% CI=1.41-1.71) and persistent difficulty in ADL function (13% vs 5%, adjusted HR=1.85, 95% CI=1.58-2.16). CONCLUSION Middle-aged persons who report a history of arthritis are more likely to develop mobility and ADL difficulties as they enter old age. This finding highlights the need to develop interventions and treatments that take a life-course approach to preventing the disabling effect of arthritis.