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Published April 8, 2020

Frailty

Frailty refers to a decline in one’s physiological reserve with age, leading to increasing vulnerability to adverse health outcomes from even minor stressor events. Frailty is more common in women than men, and frail individuals are at increased risk for long-term disability and death.

In this section, we will review:

  • Pathophysiology

  • Assessment

  • Prevention and Management

  • Outcomes Associated with Frailty

Pathophysiology

Frailty is characterized by a diminished ability to respond to stressors. In the diagram below, both the frail individual (red line) and the nonfrail individual (green line) experience an acute loss of function in response to an acute illness, such as a pneumonia. For the nonfrail individual, the loss of function is small, followed by rapid recovery. However, for the frail individual, the same acute illness causes a more pronounced loss of function and a prolonged recovery. In fact, the frail individual may never return to the same functional status he or she had before the illness.

Functional Status in Frail and Nonfrail Individuals

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(Adapted from: Frailty in Older People. Lancet 2013.)

The exact pathophysiology of frailty is not known but is believed to reflect an interplay among chronic inflammation, impaired immunity, and a diminution in physiological reserve across multiple organ systems (see figure below). These effects go beyond what is expected with aging. The changes with frailty can be subtle and, thus, are often dismissed as a normal part of aging.

Although the prevalence of frailty increases with age, it is not limited to the elderly. For instance, multiple studies have shown a higher burden of frailty, regardless of age, in people living with HIV infection, people with hemophilia, and Native Americans.

Pathophysiology of Frailty

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(Source: Frailty in Older People. Lancet 2013.)

Assessment

Various methods can be used to measure frailty. One of the most common is the frailty phenotype, defined by the presence of three of the following five characteristics:

  • unintentional weight loss

  • self-reported exhaustion

  • low physical activity

  • slow walking speed

  • weakness

This frailty-assessment method was based on prospective data from the Cardiovascular Health Study of 5210 men and women aged 65 years or older. Compared with individuals who had fewer than three frailty characteristics, those with three or more characteristics had a greater incidence of adverse outcomes at 3- and 5-year follow-up.

Frailty Phenotype Characteristics

CriterionMethod of Measurement
Weight lossAt least 10 pounds or 5% body weight lost in past year
Self-reported exhaustionSelf-report: feeling tired all the time
Low physical activityUnable to walk/requires help to walk
Slow walking speedTimed Up-and-Go test >19 seconds
WeaknessGrip strength in the lowest 20% (using handheld dynamometer)

Another frailty-assessment method, the Rockwood Frailty Index , considers as many as 40 deficits in an individual, including symptoms (e.g., shortness of breath), signs, disabilities (e.g., inability to walk without assistance), and laboratory and radiographic data. This index has been validated in several cohorts. Compared to the categorical phenotype model, the Rockwood Frailty Index quantifies the burden of frailty as a continuous measure.

Prevention and Management

Managing frailty requires a holistic approach, incorporating the assistance of doctors, nurses, physiotherapists, occupational therapists, and social workers. Close contact with caregivers and review of medication are important in assessing the impact of illness and symptoms. Patient preferences (what “matters most” to them) is critical in caring for these vulnerable people.

No medications have been shown to reverse or prevent frailty. Several approaches to reducing the prevalence of frailty or complications associated with frailty have been investigated. These include:

  • Inpatient acute care in hospital units for the elderly and outpatient comprehensive geriatric assessment programs

  • Exercise, which has important physiological effects on the brain, endocrine, immune, and musculoskeletal systems

  • Diet: data on nutritional assessment in frailty are mixed but suggest a benefit of maintaining a balanced diet with protein, fiber, and appropriate fluid intake

  • Recognition and treatment of depression and other psychiatric illness

Outcomes Associated with Frailty

Older adults often are not included in prevention, screening, and therapeutic intervention studies. For instance, multiple primary- and secondary-prevention trials have shown a benefit of statins in reducing cardiovascular events and mortality. Most of those trials either excluded, or included very few, individuals aged >80 years. A prospective cohort study of Physicians’ Health Study participants indicated that the benefit of statins may be diminished in frail older adults.

Similarly, symptomatic aortic stenosis is associated with high mortality. Often, affected patients are unable to undergo surgical aortic valve replacement, given the risks associated with surgery. Transcatheter aortic valve replacement (TAVR) has emerged as an alternative therapy in high-risk patients with aortic stenosis (PARTNER trial). However, in a post hoc analysis of 244 patients, individuals in the frail group were found to have increased mortality and worse outcomes than nonfrail participants.

Numerous studies have shown that frailty is better than chronological age in predicting risk of postoperative complications , length of hospital stay, and discharge to a skilled nursing or assisted-living facility. The Edmonton Frail Scale and modified Hopkins Frailty Assessment score are tools used in assessing frailty perioperatively, with the aim of improving these outcomes.

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