Clinical Frailty Scale

Original Editor - Vidya Acharya

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Objective[edit | edit source]

Clinical Frailty Scale (CFS) is used commonly to assess frailty. The CFS is utilized to predict the outcomes of older people hospitalized with acute illnesses.[1] The CFS is commonly used to predict health outcomes that are significantly associated are mortality, comorbidity, functional decline, mobility, and cognitive decline.

The scale was developed from the Canadian Study of Health and Aging, and considers the things that most often go wrong as age-related health deficits accumulate. It predicts adverse health outcomes in a variety of settings, including acute care. It provides a summary tool for clinicians to assess frailty and fitness. Initially, it was scored on a scale from 1 (very fit) to 7 (severely frail). It was modified to a 9-point scale to include very severely frail and terminally ill.[1] It evaluates specific domains, including comorbidity, function, and cognition, to generate a frailty score ranging from 1 (very fit) to 9 (terminally ill).[2][3]

  • A 9-point scale that summarizes the overall level of fitness or frailty of an older adult after they had been evaluated by a health care professional.
  • Higher scores mean greater risk.
  • It is not a questionnaire.
  • Grading requires clinical judgement that is based in part on screening criteria, and which then considers what broadly stratifies degrees of fitness and frailty.
  • Scale focuses on items that can be readily observed without specialist training, including mobility, balance, use of walking aids, and the abilities to eat, dress, shop, cook, and bank; scoring should match the description, and should not be based solely on the pictures that accompany each level.

Intended Population[edit | edit source]

The frail elderly population, all individuals over the age of 65 years should be screened for frailty.

Method of Use[edit | edit source]


It can be readily be administered in a clinical setting. Applying the CFS to patients is quick and requires data collection by watching the patient (mobilize), inquiring about their habitual physical activity and ability. The clinicians assess whether 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[2]. A person with a score ≥of 5 is considered frail.[1]

Technique[edit | edit source]

The scale can be introduced by saying something like: “I’d like to know how you are [your parent is] doing overall.” The clinician can inquire about[3]:

  • How the person moved, functioned, thought, and felt about their health over the last two weeks?
  • How active the person is?
  • Which medications the patient is taking; experienced clinicians can quickly estimate which illnesses are likely to be present from what medications are being prescribed and/or used?

Using the CFS to Grade Degrees of Fitness Prior to the Level of Risk Associated with Frailty[edit | edit source]

Level 1– Very Fit: People who are robust, active, energetic, and motivated. These people commonly exercise regularly. They are among the fittest for their age.

Level 2 – Fit: Previously known as well: People who have no intense disease symptoms but are less fit than level 1. Often, they exercise or are very active occasionally, e.g., seasonally.

Level 3 – Managing Well: People whose medical problems are well controlled, but are not regularly active beyond routine walking.

Using the CFS to Grade Clinically Meaningfully Increased Risk[edit | edit source]

Key factors for Levels 4 to 7are mobility, function, and cognition. Each level reflects high-order aspects of health: they integrate a lot of information. Mobility problems exist like an ankle sprain, diabetic nerve damage, dehydration, heart failure, kidney damage, or pneumonia. In consequence, these key domains are sensitive signs of health but are not very specific. Impaired function and impaired mobility are commonly accompanied by several illnesses, which result in frailty.[3]

Level 4 – previously “Vulnerable” is now Living with Very Mild Frailty-While not dependent on others for daily help, often symptoms limit activities. A common complaint is being “slowed-up” and being tired during the day.[1]

Level 5 – Living with Mild Frailty (previously “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.[1][3]

Level 6 – Living with Moderate Frailty (previously “Moderately Frail”): They 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 (standby) with dressing.[3][1]

Level 7 – Living with Severe Frailty (previously “Severely Frail”): is characterized by progressive dependence in personal ADLs. Completely dependent on personal care from whatever cause (physical or cognitive). Even though they seem stable and not at high risk of dying (within six months). People living with severe frailty can be mobile. Progressively taking to bed—but not being largely bedfast—is the hallmark of the progression of severe frailty.

Using the CFS in People Towards the End of Life[edit | edit source]

The understanding of what happens at the end of life has evolved in relation to its association with ageing. Older people who are terminally ill are much more likely to receive formal palliative care esp in cancer than if they have a disease with a recognized terminal phase, such as dementia or heart failure.[3]

Level 8 – Living with Very Severe Frailty (previously “Very Severely Frail”): These patients are completely dependent, approaching the end of life. Typically, they could not recover even from minor illnesses. A frail person often takes to bed for weeks, prior to dying. This is either heralded by an identifiable episode, such as an infection, or the person just slips away, commonly after some days of reduced oral intake. Very severely frail people who die without a single apparent cause typically follow such a trajectory, commonly with little pain or even distress, often, except impaired bowel function. [3]

Level 9 – 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[1]. This level is notable for being the only level in which the current state surpasses the baseline state. The terminally ill person might have been operating at any frailty level at baseline. On the CFS card, a person in this category is pictured seated in a chair, reflecting the fact that many older adults who die with a single system illness (like cancer), have a reasonable level of function until about the very end. In case a terminally ill person is completely dependent for personal care at baseline, they will be scored as Level 8.[3]

Final Hints About Scoring and Next Steps[edit | edit source]

Individual characteristics will vary within each level of the CFS. About 80% or more of people fit the description offered for a given level. If they fit two categories equally well, in routine care it is best to score the scale at the higher or more dependent level. Clinicians also need to recognize the possibility of some variability in judgement in specific circumstances.[3]

Scoring the CFS in People with Cognitive Impairment[edit | edit source]

The degree of dementia is correlated to the level of frailty.[3]

  • Mild dementia would go with mild frailty. In both cases, the person is independent in their personal or basic ADLs, but dependent on one or more instrumental ADLs (such as finance, transportation, heavy housework, medications).
  • Recent memory is very impaired in people with moderate dementia, even though they seemingly can remember their past life events well. As with moderate frailty, they can do their personal care with prompting or set-up.
  • In severe dementia, as in severe frailty, people have progressive difficulty in performing personal ADLs and require increasing amounts of hands-on assistance.

Evidence[edit | edit source]

Reliability[edit | edit source]

Clinical Frailty Scale is a reliable instrument to identify frailty in the emergency department. It might provide useful information for decision-making with triage, disposition, and treatment.[4] Applying the CFS to patients requires a clinical judgment of the examining clinician and thus may lead to inter-observer variation[1]. The inter-rater reliability of the CFS is very good, however, several biases may play a role in scoring, especially with clinicians who are inexperienced using the scale[5]. Considering this, a new classification tree to improve CFS scoring by inexperienced raters has been created. The classification tree is essentially a step-by-step guide to assess a patient's independence, multi-morbidity, fatigue and activity levels. The questions are based on each level of the clinical frailty scale and links each level to a simple question asked in routine assessments and no specialist training is required. The study aiming to assess the intra-rater reliability between a 'CFS classification tree' and 'CFS scoring' by novice and expert raters in 115 older adults showed an overall agreement for the CFS classification tree was good with an ICC score of above 0.800 when compared to both expert and classification tree and novice and classification tree scoring.[5][6]

Validity[edit | edit source]

CFS score is a valid diagnostic instrument to measure frailty in older hospitalized patients and patients in the emergency department.[7] CFS-Korean version is a valid scale for measuring frailty in older Korean patients.[8] This scale has largely not been validated in younger people as a disability in younger people (including both acquired, as in spinal cord injury, and life-long, as in intellectual disability) does not have the same meaning for prognosis that it does with age-related disability[3].

Miscellaneous[edit | edit source]

  • CFS is seen as one of the most promising and practical ways of screening frailty in routine assessment and especially in acute care as it combines clinical judgment with objective measurement. It provides valuable information to guide patient care and health policy development.[2]
  • Studies have shown that the CFS is mostly used within geriatric medicine, cardiology, intensive care, general medicine, emergency medicine, surgery, and dialysis. [2]
  • Research has suggested that CFS can be used as a tool that can guide the rationing of critical care resources if they become overwhelmed in the COVID-19 pandemic.[2]

Links[edit | edit source]


References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Mendiratta P, Latif R. Clinical Frailty Scale. StatPearls [Internet]. 2020 Jun 22.
  2. 2.0 2.1 2.2 2.3 2.4 Church S, Rogers E, Rockwood K, Theou O. A scoping review of the Clinical Frailty Scale. BMC geriatrics. 2020 Dec;20(1):1-8.
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 Rockwood K, Theou O. Using the clinical frailty scale in allocating scarce health care resources. Canadian Geriatrics Journal. 2020 Sep;23(3):210.
  4. Kaeppeli T, Rueegg M, Dreher-Hummel T, Brabrand M, Kabell-Nissen S, Carpenter CR, Bingisser R, Nickel CH. Validation of the clinical frailty scale for prediction of thirty-day mortality in the emergency department. Annals of emergency medicine. 2020 Sep 1;76(3):291-300.
  5. 5.0 5.1 Accessed on 27/2/21
  6. Theou O, Pérez-Zepeda MU, van der Valk AM, Searle SD, Howlett SE, Rockwood K. A classification tree to assist with routine scoring of the Clinical Frailty Scale. Age and Ageing. 2021 Feb 19.
  7. Stille K, Temmel N, Hepp J, Herget-Rosenthal S. Validation of the Clinical Frailty Scale for retrospective use in acute care. European Geriatric Medicine. 2020 Dec;11(6):1009-15.
  8. Ko RE, Moon SM, Kang D, Cho J, Chung CR, Lee Y, Hong YS, Lee SH, Lee JH, Suh GY. Translation and validation of the Korean version of the clinical frailty scale in older patients. BMC geriatrics. 2021 Dec;21(1):1-8.