Comprehensive Geriatric Assessment

Introduction

Comprehensive Geriatric Assessment (CGA) is a multidimensional, interdisciplinary diagnostic and treatment process that identifies the medical, functional, psychological and social problems of a frail or vulnerable older person, in order to develop a coordinated, integrated plan for treatment, rehabilitation and long-term support.¹ It is the defining methodology of geriatric medicine, distinguishing it from a standard single-system medical clerking.

CGA matters because it is one of the few interventions in geriatric medicine with robust trial evidence of benefit: a Cochrane review of CGA delivered to hospitalised older people found that patients were significantly more likely to be alive and living in their own home at follow-up, and less likely to experience functional decline, compared with usual care.² This makes it a high-yield topic - the exam-relevant point is not just knowing the domains, but why the process itself changes outcomes.

CGA should be offered to frail older people rather than to everyone over a particular age - the benefit is concentrated in those with frailty, multimorbidity or one of the frailty syndromes, and applying a full multidimensional assessment to a fit, independent older person with a single acute problem consumes considerable resource for little gain. Identifying who needs it, using a frailty screening tool, is therefore the first step of the process rather than a preliminary to it.

Why CGA differs from a standard clerking

A standard medical assessment is organised around the presenting complaint and body systems, aiming primarily at diagnosis and immediate treatment of the acute problem. CGA is organised around domains of the whole person, explicitly surfacing issues that a single-system assessment would miss - a patient admitted with pneumonia may also have unrecognised cognitive impairment, a home environment no longer safe for their mobility, and a medication list that has never been reviewed as a whole.

The domains of CGA

Medical domain in detail

• Full problem list, including chronic conditions that may not be the reason for the current presentation but affect overall risk and management
• Medication review, screening explicitly for polypharmacy, high-risk drug combinations, and deprescribing opportunities - see ³
• Nutrition: screening (e.g. MUST score), weight trend, swallowing assessment where indicated
• Continence: urinary and faecal, since new incontinence is itself a frailty syndrome warranting assessment rather than passive management with pads
• Sensory impairment: uncorrected visual or hearing loss contributes to falls, delirium risk and social withdrawal, and is frequently under-assessed

Functional domain in detail

Assessed using structured tools such as the Barthel Index (basic activities of daily living) and instruments assessing instrumental activities of daily living (managing medications, finances, using the telephone, shopping). Establishing the patient's baseline function before the current illness is essential, both to set a realistic rehabilitation target and to recognise how much of the current presentation represents acute change versus chronic baseline.

Psychological and cognitive domain in detail

Screening for cognitive impairment (using a tool such as the 4AT for delirium screening, or a longer cognitive assessment where dementia is suspected - see ⁴) and for depression (which is common, under-recognised, and can itself impair apparent cognitive performance - 'pseudodementia'). Distinguishing delirium, dementia and depression is a core, frequently examined skill within this domain.

Social and environmental domain in detail

Who else lives with or supports the patient, the adequacy and sustainability of any existing care package, the physical safety and suitability of the home environment, and the presence of any safeguarding concerns. Carer strain is assessed explicitly, since carer breakdown is a common and preventable precipitant of crisis presentation and admission - see ⁵.

The interdisciplinary team

CGA is delivered by a team, not a single clinician, with each discipline contributing a distinct lens on the same patient.

The team meets regularly (often via a structured multidisciplinary team meeting) to synthesise findings from each domain into a single, prioritised problem list and coordinated plan, rather than each discipline pursuing a separate, unlinked set of recommendations.

Where CGA is delivered

• Acute frailty units: rapid CGA at the front door of the hospital, aiming to identify frailty early and avoid unnecessary prolonged admission
• Orthogeriatric wards: CGA integrated with fracture/surgical care, shown to reduce mortality and improve outcomes after hip fracture in particular
• Day hospitals and outpatient clinics: CGA without the need for admission, for patients who can attend but need multidimensional assessment
• Community and primary care: increasingly delivered proactively for patients identified as frail via the electronic Frailty Index, before a crisis occurs - see ⁶
• Pre-operative assessment: CGA before elective major surgery in frail patients, to optimise modifiable risk factors and set realistic expectations

Tools used within CGA

CGA is a process rather than a questionnaire, but a set of validated instruments is commonly used within it to make each domain assessment structured and comparable over time.

Turning assessment into a plan

CGA is only as useful as the plan it produces. A good CGA-derived plan is:

1. Prioritised: addressing the problems that matter most to the patient's function, safety and preferences first, not an exhaustive list attempted simultaneously
2. Coordinated: a single plan the whole team and the patient understand, rather than separate discipline-specific instructions
3. Goal-oriented: explicitly incorporating what the patient themselves wants to achieve, whether that is returning home safely, maintaining independence, or comfort-focused care
4. Realistic: matched to the patient's frailty, prognosis and rehabilitation potential, avoiding both therapeutic nihilism and unrealistic expectation of full recovery to a prior baseline
5. Reviewed regularly: as the patient's condition, response to treatment, and preferences evolve - CGA is iterative, not a single completed document

CGA before surgery

Preoperative CGA - sometimes delivered through a dedicated perioperative medicine for older people service - has become one of the clearest applications of the process outside acute medicine, because frailty predicts postoperative outcome substantially better than age or ASA grade alone.

• Risk stratification: identifying frailty, cognitive impairment and functional limitation that predict postoperative delirium, complications, prolonged stay and mortality
• Prehabilitation: structured exercise, nutritional optimisation, anaemia correction, smoking and alcohol reduction in the weeks before surgery, which measurably improves recovery
• Medication optimisation: identifying and adjusting drugs that increase perioperative risk, and planning anticoagulant and antiplatelet management
• Delirium prevention planning: flagging high-risk patients so that preventive measures are in place from the moment they arrive on the ward
• Realistic shared decision-making: discussing likely functional outcome and recovery trajectory, not just operative mortality, so a patient can weigh whether the expected benefit matches what matters to them

Red flags and pitfalls

• Missing the medical domain in favour of purely social/functional assessment, or vice versa - both extremes miss important, actionable findings
• Failing to establish a genuine pre-morbid baseline, leading to unrealistic rehabilitation goals or, conversely, underestimating potential for recovery
• Treating CGA as a one-off event rather than revisiting the plan as the picture evolves
• Excluding the patient's own goals and preferences from the plan, particularly in decisions about ceiling of care

Prognosis and impact

The evidence for CGA is among the strongest in geriatric medicine: compared with usual care, hospitalised older people receiving CGA are more likely to be alive and in their own home at follow-up, more likely to experience improved cognition, and less likely to be readmitted, translating structured, well-coordinated assessment directly into better real-world outcomes.²

This evidence base is why CGA has moved from being a specialist inpatient geriatric medicine tool to something increasingly delivered earlier - at the front door of hospitals, proactively in the community for patients identified as frail, and before elective surgery - reflecting the principle that identifying and addressing multidimensional problems earlier produces better outcomes than reacting only once a crisis has occurred.

The strongest single application remains orthogeriatric care after hip fracture, where routine geriatrician involvement alongside the orthopaedic team - rather than referral only when a problem arises - reduces mortality, delirium, length of stay and time to surgery. This model, now standard in UK practice and audited nationally, is essentially CGA delivered in parallel with surgical care, and is the clearest demonstration that the process itself, rather than any individual component of it, is what produces the benefit.