Effect of structured physical activity on prevention of major mobility disability in older adults: The LIFE study randomized clinical trial

Abstract

IMPORTANCE: In older adults reduced mobility is common and is an independent risk factor for morbidity, hospitalization, disability, and mortality. Limited evidence suggests that physical activity may help prevent mobility disability; however, there are no definitive clinical trials examining whether physical activity prevents or delays mobility disability. OBJECTIVE: To test the hypothesis that a long-term structured physical activity program is more effective than a health education program (also referred to as a successful aging program) in reducing the risk of major mobility disability. DESIGN, SETTING, AND PARTICIPANTS: The Lifestyle Interventions and Independence for Elders (LIFE) study was a multicenter, randomized trial that enrolled participants between February 2010 and December 2011, who participated for an average of 2.6 years. Follow-up ended in December 2013. Outcome assessors were blinded to the intervention assignment. Participants were recruited from urban, suburban, and rural communities at 8 centers throughout the United States. We randomized a volunteer sample of 1635 sedentary men and women aged 70 to 89 years who had physical limitations, defined as a score on the Short Physical Performance Battery of 9 or below, but were able to walk 400 m. INTERVENTIONS: Participants were randomized to a structured, moderate-intensity physical activity program (n = 818) conducted in a center (twice/wk) and at home (3-4 times/wk) that included aerobic, resistance, and flexibility training activities or to a health education program (n = 817) consisting of workshops on topics relevant to older adults and upper extremity stretching exercises. MAIN OUTCOMES AND MEASURES: The primary outcomewas major mobility disability objectively defined by loss of ability to walk 400 m. RESULTS: Incident major mobility disability occurred in 30.1%(246 participants) of the physical activity group and 35.5%(290 participants) of the health education group (hazard ratio [HR], 0.82 [95%CI, 0.69-0.98], P = .03). Persistent mobility disability was experienced by 120 participants (14.7%) in the physical activity group and 162 participants (19.8%) in the health education group (HR, 0.72 [95%CI, 0.57-0.91]; P = .006). Serious adverse events were reported by 404 participants (49.4%) in the physical activity group and 373 participants (45.7%) in the health education group (risk ratio, 1.08 [95%CI, 0.98-1.20]). CONCLUSIONS AND RELEVANCE: A structured, moderate-intensity physical activity program compared with a health education program reduced major mobility disability over 2.6 years among older adults at risk for disability. These findings suggest mobility benefit from such a program in vulnerable older adults. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01072500. Copyright 2014 American Medical Association. All rights reserved.