At the tipping point: Predicting severe mobility difficulty in vulnerable older women

OBJECTIVES: To identify clinical measures that aid detection of impending severe mobility difficulty in older women. DESIGN: Cross-sectional and longitudinal cohort study. SETTING: Urban community in Baltimore, Maryland. PARTICIPANTS: One thousand two community-dwelling, moderate to severely disabled women aged 65 and older in the Women's Health and Aging Study I. MEASUREMENTS: Self-report and performance measures representing six domains necessary for mobility: central and peripheral nervous systems, muscles, bones and joints, perception, and energy. Severe mobility difficulty was defined as usual gait of 0.5 m/s or less, any reported difficulty walking across a small room, or dependence on a walking aid during a 4-m walking test. RESULTS: Four hundred sixty-seven out of 984 (47%) had severe mobility difficulty at baseline, and 104/474 (22%) developed it within 12 months. Baseline mobility difficulty was correlated with poor vision, knee pain, feelings of helplessness, inability to stand with feet side by side for 10 seconds, difficulty keeping balance while dressing or walking, inability to rise from a chair five times, and cognitive impairment. Of these, knee pain (odds ratio (OR)=1.74, 95% confidence interval (CI)=1.05-2.89), helplessness (OR=1.87, 95% CI=1.10-3.24), poor vision (OR=2.03, 95% CI=1.06-3.89), inability to rise from a chair five times (OR=2.50, 95% CI=1.15-5.41), and cognitive impairment (OR=4.75, 95% CI=1.67-13.48) predicted incident severe mobility difficulty within 12 months, independent of age. CONCLUSION: Five simple measures may aid identification of disabled older women at high risk of severe mobility difficulty. Further studies should determine generalizability to men and higher-functioning individuals.