Maintaining mobility and preventing disability
Many people worry about not being able to move around as well when they get older. They fear they won’t be able to continue their favourite activities, visit their favourite places, or keep up with everyday tasks.
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Mobility — the ability to move or walk freely and easily — is critical for functioning well and living independently. As we age, we may experience changes to our mobility. There are many reasons for these changes, including changes in gait (how we walk), balance, and physical strength.
All of these can increase the number and severity of falls and make it harder for older adults to go out and visit with friends and family and continue doing their activities independently. Older adults who lose their mobility are less likely to remain living at home; have higher rates of disease, disability, hospitalisation, and death; and have poorer quality of life.
Researchers are working on this issue because it’s not only a matter of physical health, but also the social and emotional well-being of older adults.
NIA-supported researchers are identifying risk factors for physical disability and developing and testing ways to prevent or reverse loss of mobility to help older adults maintain independence. For example, long-running observational studies, such as the Women’s Health and Aging Study II and the Health, Aging, and Body Composition Study, examine functional decline and how it differs by race and sex.
“One of our goals is to continue focusing on research aimed at maintaining independence in mobility in old age,” said Sergei Romashkan, M.D., Ph.D., chief of the NIA Division of Geriatrics and Clinical Gerontology Clinical Trials Branch.
Older adults often lose physical function after hospitalisation or falls, or if they have movement-related disorders such as Parkinson’s disease. People who have lost physical function may face difficulty with activities of daily living (ADLs), such as eating, bathing, dressing, or using the bathroom without aid. Researchers are investigating ways to improve physical function following hospitalisation that would enable older adults to recover and “age in place” independently at home, avoiding costly institutional care.
A lack of physical activity or exercise can also make it more likely that a person will experience loss of mobility as they age. The increasing incidence of sedentarism (sitting too much) is a growing health concern: Too many older adults don’t get enough physical activity and spend too much time sitting daily. Some interventional studies have found positive results of physical activity and exercise on continued mobility.
Following are examples of promising NIA-funded studies in this area.
Home improvements to help older adults remain functional
Two-thirds of older adults discharged from the hospital each year face new difficulty with ADLs, including walking, and are unable to take care of themselves when they leave the hospital.
Most adults strongly prefer to live at home, but many have difficulty taking care of themselves after a hospitalisation. To date, there has been little research on integrated health and housing interventions to improve physical function.
The United States NIA-supported CAPABLE (Community Aging in Place, Advancing Better Living for Elders) home-based intervention program has been shown to be effective in increasing mobility, functionality, and the capacity to “age in place” for low-income older adults. CAPABLE evolved from another NIA-funded study, ABLE (Advancing Better Living for Elders), which provided older adults home-based occupational and physical therapy, along with home modifications to reduce physical disability and improve quality of life.
CAPABLE combines evidence-based nursing, occupational therapy, and handy worker services to help older adults function at home and prevent costly institutional care. Participants enrolled in the program include low-income older adults age 65 or older with mild or no cognitive impairment who had trouble with at least one ADL. Over five months, participants work with a registered nurse who visits their home three to four times and an occupational therapist who visits four to six times. Services include management of pain, medication, and depressive symptoms. CAPABLE also features a home repair service person who performs up to US$1,300 in home repairs, modifications, and may purchase assistive devices. Participants don’t have to pay for services or repairs, rather, the costs of about US$3,000 per person are covered by the program’s organisation.
Using motivational interviewing and action planning techniques, the older adult takes the lead in working with the team to identify barriers to overcome and specific functional goals they would like to achieve (such as walking down stairs, bathing or cooking independently, or reducing pain). This participant-led approach is a major factor in the program’s success.
For example, if the participant wants to bathe safely but fears slipping and falling in the tub, the nurse might partner with the participant to identify issues that can affect balance, like pain or muscle weakness; the occupational therapist could teach strengthening and balance exercises and ways to get in and out of the tub safely; and home repair technicians could install safety features such as grab bars and nonslip treads.
Each service builds on the others by increasing the participants’ capacity to function at home. This may decrease hospitalisation and nursing home stays by improving medication management, problem-solving ability, strength, balance, mobility, nutrition, and home safety, while decreasing isolation, depression, and fall risk.
“The program is tailored to the participants’ specific goals that fit their priorities, and we’re not prescriptive about what those goals are,” said Sarah Szanton, Ph.D., R.N., A.N.P., F.A.A.N., who developed the program and is director of the Center on Innovative Care in Aging at the Johns Hopkins School of Nursing in Baltimore. “In addition, we’re addressing participants and their environments at the same time, which is a motivating factor.”
Studies show CAPABLE improves function and lowers hospitalisation and nursing home rates. When starting the program, participants in one study had difficulty with an average of 3.9 of 8 ADLs, which decreased to two ADLs after five months. In addition, 65% reported less difficulty in performing instrumental ADLs (such as shopping, cooking, paying bills, or taking medications) and more than 50% said their depressive symptoms improved. According to another study, older adults who participated in the program had a 30% drop in reporting difficulties or needing assistance in performing ADLs compared with those who only had social visits from a research assistant after five months. Participants were also more likely to report that the program made their life easier, made their home safer, kept them living at home, helped them take care of themselves, and helped them gain confidence in managing daily challenges.
In addition to improving quality of life, CAPABLE is cost-effective. According to a Centers for Medicare and Medicaid Services evaluation of its CAPABLE demonstration project, the program costs US$2,825 per participant on average and yields a 7-to-1 return on investment of US$22,000 in reduced Medicare costs over two years. The lower costs were due to associated reductions in both inpatient and outpatient expenditures, such as hospital stays and readmissions.
“Sometimes just inexpensive things working all together can make a big difference in improving patients’ functionality,” said Szanton.
To date (30 November 2020), about 2,500 older adults have participated in CAPABLE, which is currently offered through 31 organizations in 15 states in the United States and Australia. Facilitators include health care systems, Area Agencies on Aging, Medicare Advantage health plans, state and local governments, insurance companies, skilled nursing facilities, nursing homes, Veterans Administration centres, home health care agencies, and health care and housing nonprofits such as Meals on Wheels and Habitat for Humanity.
Although CAPABLE is not currently covered as a Medicare benefit, this could change in the future. Szanton would like to see Medicare’s annual wellness visit periodically occurring at a patient’s home so their environment could be observed in relation to tasks such as bathing, dressing, or grooming. CAPABLE is also being tested by the Visiting Nurse Service of New York in an NIA-supported study of people who lost physical function after recent hospitalisations.
How physical activity can prevent major mobility disability
Many studies have shown that regular exercise improves physical performance. But little is known about whether exercise can actually help prevent major mobility disability, defined as the inability to walk a quarter of a mile, or four blocks. Researchers sought to learn more about this connection through the Lifestyle Interventions and Independence for Elders (LIFE) study, which they designed to assess whether a long-term structured physical activity program was more effective than a health education program in reducing the risk of major mobility disability in older adults who lived a sedentary lifestyle.
For the study, 1,635 participants aged 70 to 89 were randomly assigned to a structured, moderate-intensity physical activity program, or to a health education program of workshops on topics relevant to older adults. Racially and ethnically diverse participants at high risk for disability were recruited from eight university centres across the U.S. in urban, suburban, and rural communities. They had some evidence of impaired function at baseline but were all able to walk 400 meters (about a quarter of a mile) in a screening test. The objective of the intervention was to maintain this ability and prevent loss of ability to walk this distance.
The physical activity intervention involved walking (with a goal of 150 minutes a week), strength training, including the use of ankle weights, flexibility, and balance training and included attending instructor-led exercise classes twice a week at a centre and a home-based activity three to four times per week for two years. The health education program included weekly health education workshops on topics such as travel safety, health screenings, and nutrition, along with five to 10 minutes of instructor-led upper body stretching and flexibility exercises for the first 26 weeks, and then monthly sessions for the remainder of the study. Participants were assessed every six months at clinic visits for physical activity measures, including the ability to walk 400 meters.
Participation in the program was measured by attendance at sessions and by questionnaires in which participants recorded the number of hours per week they were physically active. In addition, participants’ activity was recorded for one week during each year of the trial through an accelerometer, a small belt device that measures physical activity.
Results showed that over 2.6 years, the physical activity program reduced the risk of major mobility disability by 18% compared with the health education program. These findings suggest that older adults who are vulnerable to disability can benefit from physical activity.
“The intervention was not only effective in preventing mobility disability, but it was also cost-effective,” said Marco Pahor, M.D., principal investigator of the LIFE study, director of the Institute on Aging at the University of Florida in Gainesville, and chair of aging and geriatric research at the university’s College of Medicine. “Those who started with the poorest function benefited the most from the physical activity program. The results also showed perceived benefits in walking speed and physical performance scores,” meaning people felt they were getting benefits beyond what the study could actually measure.
This ground-breaking study was the largest and longest lasting randomised controlled trial ever conducted on physical activity in older adults. Its findings have shaped several U.S. and international recommendations for physical activity in older adults, including the U.S. Department of Health and Human Services’ Physical Activity Guidelines for Americans (PDF, 14.4M).
“Beyond the specific findings on exercise, the study showed that older adults, who are traditionally excluded from large clinical trials, can be successfully recruited and retained for clinical studies, and will adhere to an exercise program,” said Jack M. Guralnik, M.D., Ph.D., co-principal investigator for the study and a professor in the Department of Epidemiology and Public Health, Division of Gerontology, at the University of Maryland School of Medicine in Baltimore. Guralnik was formerly chief of the NIA’s Laboratory of Epidemiology, Demography, and Biometry.
“We’ve come a long way in the last 20 to 25 years, but a lot more can be done,” said Guralnik. “We need to get more older adults exercising. The biggest challenge is being able to motivate people to exercise and then sustain physical activity, especially if they have mobility and functional problems.”
Taking a stand against sitting
Many older adults struggle to engage in health-enhancing physical activity and spend, on average, between nine and 13 hours a day sitting.
There is little scientific evidence on how best to interrupt long periods of sedentary behaviour, and few studies that have focused on physical activity interventions to reduce such behaviour. Still, interventions focused on standing have been shown to reduce sedentary behaviour up to two hours per day. Also, epidemiological studies have shown associations between self-reported sedentary behaviour and increased risks of death and metabolic outcomes, but very few prospective studies have used objective measures of sedentary behaviour.
After an NIA summer workshop series to address the lack of scientific evidence in this area, researchers at the University of California, San Diego (UCSD) launched the Sedentary Time and Aging Research (STAR) program. The goal is to provide more rigorous and comprehensive evidence on how to interrupt extended sitting time and its consequences for healthy aging in premenopausal women. The research includes investigating novel mechanisms important for healthy aging, as well as investigating behaviours such as standing and brief sit-to-stand transitions that expend little energy but engage muscles, improve postural blood flow, and may impact physical functioning in older adults.
This ongoing, five-year program includes three protocols:
- A randomised crossover clinical trial* of postmenopausal women to test whether different interruptions to prolonged sitting improve metabolism
(*A type of clinical trial in which all participants receive the same two or more treatments, but the order in which they receive them depends on the group to which they are randomly assigned.)
- A randomised controlled trial designed to assess ways of interrupting sitting in overweight, postmenopausal women
- A prospective study using machine-generated algorithms to assess how sitting, standing, moving from sitting to standing, and physical activity are related to biomarkers (biological indicators of disease) of healthy aging, physical functioning, and mortality
In one study, researchers at UCSD are partnering with the American Heart Association to assess three-month changes in sitting time, standing time, physical activity, and blood pressure among 250 postmenopausal Latino women aged 55 and older who are obese, spend at least eight hours a day sitting, and have increased risk for cardiovascular disease. The women wear an accelerometer on their thigh, which is a small device that measures physical activities such as lying, sitting, standing, and stepping. Preliminary findings show that the association between sitting behaviour and increased fasting glucose may be higher in Latino women than non-Latino women.
“There is epidemiological evidence that sitting too much has negative effects on diabetes, mortality, and physical function, and is associated with adverse outcomes,” said John Bellettiere, Ph.D., M.P.H., M.A., an assistant professor of epidemiology in the Department of Family Medicine and Public Health and co-director of the epidemiology curriculum of the Clinical Research Enhancement through Supplemental Training (CREST Program) at UCSD. “In our most recent research, we have seen reduced mortality risk among older women — 37% — with higher rates of standing. The lower mortality risk was observed just by replacing sitting with standing still — our participants did not have to move around, although when they did walk around while standing, the reduction in mortality risk was even larger.”
In another 12-week study to assess the effect of changes in standing and the number of sit-to-stand transitions on physical, emotional, and cognitive functioning, sedentary postmenopausal women age 55 and older are randomly assigned to various combinations of these interventions:
- One-on-one, in-person, and phone health coaching sessions aimed at goal setting, implementing strategies, overcoming barriers, and relapse prevention
- An activity monitor to measure sitting and standing time and to enable health coaches to provide feedback and assist in developing an action plan
- Tools to prompt standing or sit-to-stand transitions such as wearable wrist devices, standing desks or tables, mechanical and/or electronic timers, or access to mobile apps or computer programs
These interventions are aimed at reducing daily sitting time and increasing the daily number of brief sit-to-stand transitions.
“We are studying the immediate, short- and long-term effects of breaking up sitting with short periods of standing or taking brief walks during the day,” said Andrea Z. LaCroix, Ph.D., Distinguished Professor of Epidemiology and principal investigator of STAR at UCSD. “The results of these studies will provide evidence on how often we need to get up from sitting to improve how our bodies function across a spectrum of health indicators from circulation to measures of metabolism in our blood, and most importantly to maintaining mobility and extending the healthy part of longevity.”
In the future, research on maintaining independence in older adults might include more practical studies to evaluate strategies for implementation in real-world settings and interdisciplinary studies on mobility that integrate expertise in muscle physiology and neurology, according to Romashkan. It might also include developing more meaningful quality-of-life measures and intervention studies to determine how specific mechanisms of physical activity enhance mobility function in older adults, which could lead to improved exercise interventions or alternative treatments, he added.
And with increased mobility, older adults can move around and perform daily activities more easily and safely and continue to live as independently as possible.
3 January 2020.