Sensorimotor and psychosocial determinants of 3-year incident mobility disability in middle-aged and older adults

Objective: To identify sensorimotor and psychosocial determinants of 3-year incident mobility disability. Design: Prospective. Setting: population-based sample of community-dwelling older persons. Participants: Community-living middle-aged and older persons (age: 50-85 years) without baseline mobility disability (n = 622). Measurements: Mobility disability, defined as self-reported inability to walk a quarter mile without resting or inability to walk up a flight of stairs unsupported, was ascertained at baseline and 3-year follow-up. Potential baseline determinant characteristics included demographics, education, social support, financial condition, knee extensor strength, visual contrast sensitivity, cognition, depression, presence of chronic conditions and history of falls. Results: A total of 13.5% participant reported 3-year incident mobility disability. Age ≥75 years, female sex, knee extensor strength in the lowest quartile, visual contrast sensitivity 16) were independent determinants of 3-year incident mobility disability (ORs 1.84-16.51). Conclusions: Low visual contrast sensitivity, poor knee extensor strength and significant depressive symptoms are independent determinants of future onset of mobility disability.