Clinical Frailty Scale

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Continuing Education Activity

Frailty is a multidimensional geriatric syndrome, which is characterized by an increased vulnerability to various external stressors into a serious health problem. Frailty is strongly linked to adverse outcomes, including mortality, admissions to nursing homes, and falls. The Clinical Frailty Scale is a well-validated scale used to quantify the degree of disability from frailty. This activity reviews the clinical frailty of geriatric patients and highlights the role of the Clinical Frailty Scale for use by clinicians in evaluating a patient for frailty.


  • Describe frailty as a geriatric syndrome.
  • Outline the risk factors for developing frailty.
  • Identify the various components of the Clinical Frailty Scale.
  • Summarize the clinical significance of the Clinical Frailty Scale.


Across the globe, in all countries, the number of older adults is increasing. These increases in the elderly population are making frailty an increasing concern for the healthcare system. Frailty is a multidimensional geriatric syndrome, which is characterized by an increased vulnerability to various external stressors. Frailty is associated with multiple adverse outcomes, including mortality, admissions to nursing homes, and falls. It will continue to place a substantial and increasing burden on public health and healthcare systems.[1]

Frailty is the result of cumulative cellular damage from diverse etiologies over the life of the individual. Typical aging results in loss of some homeostatic reserve in physiological systems. However, despite the loss of these reserves, individuals still function well with aging. Any homeostatic perturbation in these reserves will result in the older adult decompensating and thus causing frailty. The silent precursor to frailty is pre-frailty or latent frailty. Frailty happens from latent frailty whenever external stressors (e.g., acute illness, injury, or mental stress) occur in the older adult.[2]

Frailty can develop due to factors such as (i) socio-demographic influences (e.g. poverty, living alone, low education level); (ii) psychological factors (e.g. depression); (iii) nutritional issues (e.g. malnutrition); (iv) polypharmacy; (v) diseases and complications (inflammatory states, cancer, endocrine disorders, dementia); and (v) low physical activity.[3] Despite the importance of frailty, there is currently no internationally recognized standard definition given its complex etiology; definitions used by different frailty researchers; and the inherent difficulty in distinguishing frailty from both aging and disability. Irrespective of definitions, it is clear that frailty is an important geriatric syndrome, which is dynamic, fluctuates over time, and reflects multisystem dysfunction. Given its importance, since the mid-1990s, frailty combination scores have been developed, wherein a constellation of frailty manifestations was grouped to be able to quantify the degree of disability from frailty.[4]


Frailty measures are essential to include in clinical practice to develop various interventions for resulting disability for older adults. Over the years, several instruments for assessing frailty are in use.

One of the scales commonly used is the Clinical Frailty Scale (CFS).[5] The CFS is a validated scale. It evolved from the Canadian Study of Health and Aging. Since its publication, the CFS is in frequent use in clinical settings. It provides a summary tool for clinicians to assess frailty and fitness. The elements are derived based on the clinician’s clinical judgment. It was scored on a scale from 1 (very fit) to 7 (severely frail) upon initial publication in 2005. In 2007, however, the CFS was modified to a 9-point scale to include very severely frail and terminally ill as separate entities, which initially were lumped together. The 9-point scale provides a descriptor of a frailty stage. There is a visual chart to assist with the frailty classification. A person with a score ≥of 5 is considered frail.

Applying the CFS to patients requires clinical judgment on the part of the examining clinician and thus may be subjected to inter-observer variation. Although the CFS is touted as a quick and easy test, it does require data collection beyond that which could be collected by a cursory evaluation. It does entail watching the patient (mobilize), inquiring about their habitual physical activity and ability. It requires the clinicians to assess if the patient can independently perform tasks such as bathing, dressing, housework, going upstairs, going out alone, going shopping, taking care of finances, taking medications, and preparing meals. The main advantage besides its validity is that it is easy to use and may readily be administered in a clinical setting. The CFS is utilized to predict the outcomes of older people hospitalized with acute illnesses.[6] It has also been used to help predict in-patient mortality and thus help target specialty geriatric resources within the hospital.[7] 

One of the limitations of this scale is that it combines several domains of frailty and disability and may not be as applicable as other phenotype-oriented frailty scales. The patient’s level of disability heavily weights the CFS. It is unclear if the CFS offers superior or redundant value compared to other disability scales (e.g., Katz Index).[8]


Clinical Frailty Scale Components

  • Very Fit: People who are robust, active, energetic, and motivated. These people commonly exercise regularly. They are among the fittest for their age.
  • Well: People who have no intense disease symptoms but are less fit than category 1. Often, they exercise or are very active occasionally, e.g., seasonally.
  • Managing Well: People whose medical problems are well-controlled but are not regularly active beyond routine walking.
  • Vulnerable: While not dependent on others for daily help, symptoms often limit activities. A common complaint is being “slowed-up” and being tired during the day.
  • Mildly Frail: These people usually have more evident slowing and need help in higher-order instrumental activities of daily living (IADLs) such as finance, transportation, heavy housework, medications. Typically, mild frailty progressively impairs shopping and walking outside alone, meal preparation, and housekeeping.
  • Moderately Frail: People need help with all outside activities and with keeping house. Inside, they often have problems with stairs and need help with bathing, and might need minimal assistance (stand-by) with dressing.
  • Severely Frail: Completely dependent on personal care from whatever cause (physical or cognitive). Even so, they seem stable and not at high risk of dying (within six months).
  • Very Severely Frail: These patients are completely dependent, approaching the end of life. Typically, they could not recover even from minor illnesses.
  • Terminally Ill: Approaching the end of life. This category applies to people with a life expectancy of under 6 months, which are not otherwise evidently frail.

Scoring Frailty in a Patient with Dementia: The degree of frailty corresponds to the degree of dementia. Common symptoms in mild dementia include forgetting the details of a recent event, though still remembering the event itself, repeating the same question/story, and social withdrawal. In moderate dementia, recent memory is very impaired, even though they seemingly can remember their past life events well. They can do personal care with prompting. In severe dementia, they cannot do personal care without help.

Clinical Significance

The diagnosis of frailty frequently poses a diagnostic dilemma.[9] Despite the importance of frailty, there is currently no internationally recognized standard definition given its complex etiology, definitions used by different frailty researchers, and the inherent difficulty in distinguishing frailty from aging and disability. Given the importance of frailty, several combination scores, wherein a constellation of frailty manifestations, were grouped to quantify the degree of disability from frailty. One of the scales commonly used is the Clinical Frailty Scale (CFS). This scale is well-validated and frequently used. It helps identify those patients at risk for adverse outcomes from frailty and helps implement timely preventive strategies to maximize patient outcomes. 

Enhancing Healthcare Team Outcomes

The integration of frailty measures in clinical practice is crucial for developing interventions against age-related conditions (in particular, disability) in older persons. Multiple instruments have been developed over the years to capture frailty. A 9-point scale exists where each point corresponds with a written description of frailty. It is complemented by a visual chart to assist with the classification of frailty. Score ≥5 is considered to be frail. The scale is well validated and has been tested in various clinical settings.[Level 1] This scale can be used by an interprofessional healthcare team of clinicians that includes physicians, physician assistants, nurse practitioners, nurses, pharmacists, and nutritionists, to classify frailty.[10]

*Kenneth Rockwood has given signed permission to use CFS for StatPearls use.

Article Details

Article Author

Priya Mendiratta

Article Editor:

Rafay Latif


6/20/2021 1:08:57 PM

PubMed Link:

Clinical Frailty Scale



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