Clinical Frailty Scale Calculator (Rockwood CFS)

Clinical Frailty Scale levels (1–9)

The CFS is not a checklist. You assign the single level that best describes the patient two weeks before the current illness, taking mobility, function, cognition and comorbidity together.

Version 2.0 of the scale renamed levels 4 to 8 to "living with … frailty" and clarified that level 4 describes very mild frailty. The underlying descriptions are unchanged.

Clinical Frailty Scale interpretation

The CFS describes baseline frailty and is used to inform, not to determine, decisions about assessment, rehabilitation and treatment escalation.

• 1–3Not frail

  Patient is fit or managing well. Standard clinical pathways appropriate.

• 4Vulnerable / very mild frailty

  Consider the impact of acute illness on function. May benefit from comprehensive geriatric assessment.

• 5–6Mild to moderate frailty

  Comprehensive geriatric assessment recommended. Consider function-preserving interventions and early rehabilitation.

• 7–8Severe to very severe frailty

  Discuss goals of care and advance care planning. Consider ceiling of treatment and resuscitation decisions if appropriate.

• 9Terminally ill

  Focus on comfort care and symptom management. Ensure an advance care plan is in place.

How to score the Clinical Frailty Scale

1. 1Confirm the patient is 65 or over — the CFS is validated in older adults, not in younger people with stable long-term disability.
2. 2Establish the baseline: how the patient was two weeks before the current illness, not how they are during it.
3. 3Gather function and mobility information, including instrumental activities such as shopping, finances and medication management.
4. 4Take cognition and comorbidity into account; for people with dementia, the level usually corresponds to the degree of dependence.
5. 5Choose the single level whose description best fits, and record it with the date and the source of the information.

Common pitfalls

• Scoring the acute presentation instead of the baseline. A previously independent person who is acutely unwell is not automatically severely frail.
• Using the CFS in people under 65, or in younger adults with stable long-term disability, where it is not validated.
• Using a frailty score on its own to make treatment escalation decisions. It should inform a holistic assessment, never replace one.
• Confusing the CFS with the electronic Frailty Index (eFI). The eFI is calculated automatically from coded primary care records; the CFS is a bedside clinical judgement.
• Recording a score without the collateral history that supports it — inter-rater reliability depends on how well the baseline is established.

Frequently asked questions

When should the Clinical Frailty Scale be used?

Use the CFS for patients aged 65 and over on hospital admission, in emergency departments, and during outpatient assessments. NICE recommends frailty assessment for all older adults presenting to acute care. It should reflect the patient's baseline status (2 weeks before the current illness) rather than their current acute presentation.

How do you interpret the Clinical Frailty Scale score?

Scores 1-3 (Very Fit to Managing Well) indicate the patient is not frail - standard clinical pathways. Score 4 (Vulnerable) is pre-frail - may benefit from comprehensive geriatric assessment. Scores 5-6 (Mildly to Moderately Frail) indicate frailty - CGA recommended, function-preserving interventions. Scores 7-8 (Severely to Very Severely Frail) - discuss goals of care, advance care planning, ceiling of treatment. Score 9 (Terminally Ill) - focus on comfort care and symptom management.

What is the difference between the Clinical Frailty Scale and the Rockwood score?

They are the same instrument. The scale is commonly called the Rockwood score after Kenneth Rockwood, whose group developed it for the Canadian Study of Health and Ageing, and it is also referred to as the CSHA Clinical Frailty Scale or simply the CFS.

What CFS score counts as frail?

Scores of 5 and above are generally described as frailty, with 4 regarded as vulnerable or very mild frailty and 1 to 3 as not frail. Local pathways sometimes set their own threshold for triggering comprehensive geriatric assessment.

Can the Clinical Frailty Scale be used in patients under 65?

It is not validated below 65, and it should not be used in younger people with stable long-term disability, learning disability or cerebral palsy, where the descriptions do not map onto frailty.

What is the difference between the CFS and the electronic Frailty Index?

The electronic Frailty Index is calculated automatically from coded GP records by counting accumulated deficits, and is used for population-level identification in primary care. The Clinical Frailty Scale is a clinician judgement made at the point of assessment.

Sources and further reading

• Clinical Frailty Scale — Geriatric Medicine Research, Dalhousie University
• Clinical Frailty Scale (CFS) — NHS Right Decisions

This page is reference information for registered healthcare professionals. It is not medical advice and does not replace clinical judgement, local policy, or the current version of the source guidance. Always verify scores and thresholds against your own organisation's pathway before acting on them.