Effect of Physical Activity on Self-Reported Disability in Older Adults: Results from the LIFE Study

Abstract

Background/Objectives: To test the hypothesis that a long‐term structured, moderate intensity physical activity (PA) program is more effective than a health education (HE) program in reducing the risk of s elf‐reported dependency and disability in basic activities of daily living (BADLs), disability in instrumental ADLs (IADL), and mobility disability.

Design: The Lifestyle Interventions and Independence for Elders (LIFE) study was a multicenter, single‐blinded randomized trial.

Setting: University‐based research clinic.

Participants: Thousand six hundred and thirty five sedentary men and women aged 70–89 years, who had functional limitations, defined as a score ≤9 on the Short Physical Performance Battery.

Intervention: Participants were randomized to a structured, moderate intensity PA program (n = 818) that included aerobic, resistance, and flexibility exercises or to a HE program (n = 817).

Measurements: All outcomes were derived by self‐report using periodic interviews that asked about the degree of difficulty and receipt of help during the past month. Dependency was defined as “receiving assistance” or “unable” to do ≥1 activities. Disability was defined as having “a lot of difficulty” or “unable” doing ≥1 activities. Severe disability was defined as reporting difficulty or being unable to perform ≥3 activities.

Results: Over an average follow‐up of 2.6 years, the cumulative incidence of BADL dependency was 15.2% among PA and 15.1% among HE participants (HR = 1.0, 95% CI = 0.78–0.1.3). Intervention groups had similar rates of incident BADL disability, IADL disability and reported mobility disability. Reporting severe mobility disability (HR = 0.78, 95% CI = 0.64–0.96) and ratings of difficulty on mobility tasks were reduced in the PA group.

Conclusion: A structured physical activity intervention reduces reported severe mobility disability and difficulty on mobility tasks, but not BADL and IADL disability in older adults with functional limitations.

Twenty‐three percent of the United States population, 65+ years of age report having difficulty walking or climbing stairs and 3.6 million older adults report having difficulty with basic activities like dressing and bathing.1 Reporting difficulty with, needing assistance, or being unable to perform daily tasks lead to higher utilization of health care services and loss of physical independence.2 Considerable resources are spent on managing disability among older adults, but there is limited research that evaluates strategies to prevent disability in basic and instrumental activities of daily living. A promising prevention strategy is enhancing physical activity levels, as there is well‐established epidemiological evidence that diminished physical activity is associated with onset of physical disability in older adults.3-6

The Lifestyle Interventions and Independence for Elders (LIFE) Study was a large randomized trial designed to compare the effects of a long‐term, moderate‐intensity physical activity (PA) program with a “successful aging” health education (HE) program.7, 8 The primary outcome of the LIFE study was major mobility disability defined as the loss in the ability to walk 400 m in 15 minutes without help. Here MMD was assessed objectively by observing the ability to walk 400 m. Self‐reported measures of mobility and disability inherently capture a participant's viewpoint of their ability within their own environment. This is a different construct and evaluation of this domain would provide additional insight about the effects of physical activity. The study enrolled inactive older adults 70–89 years of age who were at high risk of disability based on a lower extremity performance test, yet were community dwelling and able to walk 400 m (about a quarter mile) at baseline. Therefore, the sample enrolled in the LIFE study was well‐suited to evaluate the hypothesis that compared to a HE group, a long‐term PA program would prevent the incidence of dependency and disability in basic ADLs (BADLs) as well as disability in instrumental ADLs (IADLs), and reported mobility disability (e.g., walking a quarter mile). Copyright 2017, Copyright the Authors. Journal compilation Copyright 2017, The American Geriatrics Society