The Electronic Frailty Index (eFI) is a powerful population-screening tool integrated into UK GP computer systems. It is designed to automatically scan existing Electronic Health Records (EHR) to calculate a frailty score based on a "cumulative deficit" model.
Rather than requiring a face-to-face assessment, the eFI analyzes the accumulation of 36 distinct deficits, which are mapped across roughly 2,000 routine clinical codes.
1. The 36 Deficits Map
The 36 clinical indicators span diseases, physiological signs, symptoms, functional disabilities, and social factors:
CategoryExamples of Specific Deficits Covered
Long-Term ConditionsDiabetes, Hypertension, Heart Failure, Chronic Kidney Disease, Arthritis, Atrial Fibrillation, Stroke/Cerebrovascular Disease, Respiratory Disease.
Physical & Sensory ImpairmentsVisual Impairment, Hearing Impairment, Mobility & Transfer Problems, Foot Problems.
Symptoms & Lab ResultsAnaemia/Haematinic Deficiency, Dizziness, Hypotension/Syncope, Sleep Disturbance, Weight Loss/Anorexia, Urinary Incontinence.
Neurological & Mental HealthMemory/Cognitive Problems, Parkinsonism & Tremor.
Frailty Events & VulnerabilitiesHistory of Falls, Fragility Fractures, Osteoporosis, Skin Ulcers, Polypharmacy (taking multiple medications), Requirement for Care, Housebound status, Social Vulnerability.
2. How the Score is Calculated
The original eFI score represents a simple mathematical proportion:
\(\text{eFI\ Score}=\frac{\text{Number\ of\ Deficits\ Present}}{\text{Total\ Possible\ Deficits\ (36)}}\)
• If a patient has 9 deficits recorded, their score is \(9/36 = \mathbf{0.25}\).
• The original thresholds mapped onto four risk bands:
• Fit: < 0.12
• Mild Frailty: 0.13 - 0.24
• Moderate Frailty: 0.25 - 0.36
• Severe Frailty: > 0.36
💡 The New eFI2 Standard: Primary care software across the UK is transitioning to the eFI2. Unlike the original version where all 36 deficits were weighted equally, the eFI2 applies weighted scores based on how heavily a factor contributes to adverse risks (e.g., nursing home admission or mortality). It also introduces time limits so that historical, fully resolved events (like a past episode of depression) stop artificially inflating a patient's frailty score.
3. How GPs Use the eFI in Practice
• Proactive Screening (Not a Diagnosis): The eFI is a stratification tool, not a formal clinical diagnosis. It flags individuals at high risk so that clinicians can focus resources where they are needed most.
• Triggers Targeted Reviews: Under the NHS General Medical Services (GMS) contract, when the index automatically flags a patient as "severely frail," it prompts the GP practice to deliver a formal clinical review. This usually includes a structured medication review, a falls assessment, and a discussion about advanced care planning.
• Follow-up Verification: Patients flagged by the eFI are often targeted for a secondary, clinical assessment—such as the Clinical Frailty Scale (CFS)—to confirm their status in real life.
