The Comprehensive Geriatric Assessment

The Comprehensive Geriatric Assessment (CGA) is a structured, multidisciplinary diagnostic process used to evaluate the medical, functional, cognitive, psychological, and social status of older adults — particularly those with complex or interconnected health conditions. It differs from a standard medical examination by treating the patient as a whole system rather than addressing isolated complaints. The CGA informs individualized care planning, guides treatment decisions, and helps identify reversible conditions that a problem-by-problem clinical approach might miss. Understanding the CGA is foundational to the broader field covered across geriatric care resources on this site.

Definition and scope

The CGA is formally defined by the British Geriatrics Society and endorsed in the United States by bodies including the American Geriatrics Society (AGS) as a multidimensional, interdisciplinary diagnostic process that identifies medical problems, functional capacity, and psychosocial needs, with the goal of coordinating and integrating a long-term care plan. The scope of the CGA extends well beyond what a standard history and physical exam captures: it systematically addresses at least six domains — medical status, functional ability, cognitive function, psychological/emotional health, social circumstances, and environmental factors.

The regulatory context for geriatric assessment in the US is shaped in part by the Centers for Medicare & Medicaid Services (CMS), which recognizes elements of the CGA within several care settings. CMS Conditions of Participation for long-term care facilities (42 CFR §483.20) mandate a Resident Assessment Instrument (RAI) that incorporates functional and cognitive screening consistent with CGA principles. The regulatory environment governing geriatric practice determines how and where CGA components are reimbursed and required.

Frailty — a distinct clinical syndrome characterized by decreased physiological reserve — is a key target of the CGA. The AGS and the National Institute on Aging (NIA) recognize frailty as a separate category from disability and comorbidity, and the CGA is one of the primary tools for operationalizing that distinction in clinical settings.

How it works

A full CGA is conducted by an interdisciplinary team that typically includes a geriatrician, a nurse, a social worker, and depending on the case, a pharmacist, physical therapist, occupational therapist, or dietitian. The assessment unfolds across several structured phases:

1. Medical review — Active diagnoses, recent hospitalizations, medication list reconciliation, and relevant laboratory or imaging data are compiled and analyzed for interactions and gaps.
2. Functional assessment — Capacity to perform Activities of Daily Living (ADLs) and Instrumental Activities of Daily Living (IADLs) is scored using validated tools such as the Katz Index of Independence in ADLs and the Lawton-Brody IADL Scale. More detail on this domain is available at functional assessment and ADLs.
3. Cognitive screening — Standardized instruments such as the Mini-Mental State Examination (MMSE) or the Montreal Cognitive Assessment (MoCA) are administered. The MoCA has a maximum score of 30, with scores below 26 generally indicating the need for further evaluation. See cognitive screening tools for instrument comparisons.
4. Psychological screening — Depression screening using the Geriatric Depression Scale (GDS) or Patient Health Questionnaire-9 (PHQ-9) is standard. Anxiety and grief are also assessed.
5. Medication review — All medications — prescribed, over-the-counter, and supplements — are reviewed against tools such as the AGS Beers Criteria, which lists potentially inappropriate medications for adults aged 65 and older. The medication review and polypharmacy domain addresses this in depth.
6. Social and environmental assessment — Living situation, caregiver availability, financial resources, social isolation, and home safety hazards are evaluated. Fall risk receives dedicated scoring, typically via the Morse Fall Scale or Timed Up and Go (TUG) test — covered in detail at fall risk assessment.
7. Nutritional screening — Tools such as the Mini Nutritional Assessment (MNA) or Malnutrition Universal Screening Tool (MUST) are used, feeding into interventions documented at nutritional screening.

The full CGA can require 60 to 90 minutes of direct assessment time, with additional time for team synthesis and care plan development. Abbreviated versions — sometimes called "targeted" or "brief" CGAs — are used in emergency departments and primary care settings where full interdisciplinary evaluation is not feasible.

Common scenarios

The CGA is applied across a range of clinical contexts rather than serving as a single-use tool:

• Pre-surgical optimization — Oncology and cardiac surgery programs use CGA findings to stratify operative risk in patients aged 65 and older. The International Society of Geriatric Oncology (SIOG) recommends CGA before initiating chemotherapy or major surgery in older cancer patients, noting that CGA findings alter treatment decisions in approximately 39% of cases (SIOG Clinical Practice Guidelines, 2021 update).
• Post-acute and rehabilitation settings — After hip fracture, stroke, or major illness, the CGA guides discharge planning and rehabilitation goals. Geriatric rehabilitation programs, detailed at geriatric rehabilitation, rely heavily on CGA baselines.
• Memory and cognitive decline workup — Patients presenting with memory concerns receive CGA as part of ruling out reversible causes such as medication toxicity, depression, thyroid dysfunction, or sensory impairment masking cognitive ability. The memory problems and geriatric evaluation pathway begins with CGA components.
• Falls investigation — A patient with 2 or more falls in the preceding 12 months triggers a structured multifactorial CGA-based evaluation per AGS/British Geriatrics Society clinical practice guidelines.
• Transition from independent to assisted living — When functional decline prompts consideration of higher-level care, the CGA produces the objective data needed to match the individual to the appropriate care setting, discussed at long-term care options.

Decision boundaries

The CGA is not a universal screening tool appropriate for all older adults. Clinical judgment and resource constraints shape its application, and distinguishing when to deploy a full CGA from when a focused assessment suffices is a critical competency.

Full CGA is indicated when:
- The patient has 3 or more chronic conditions with functional interaction
- Polypharmacy involves 5 or more concurrent medications with suspected adverse effects
- Functional decline has occurred over 6 months or less without clear explanation
- A major treatment decision — surgery, chemotherapy, or transition to long-term care — requires risk stratification
- The patient meets validated frailty criteria (e.g., Fried Frailty Phenotype: 3 or more of 5 criteria positive)

Targeted or abbreviated assessment is appropriate when:
- A single domain is the clinical focus (e.g., post-fall evaluation without cognitive or functional concerns)
- Time or staffing constraints in acute settings require triage prioritization
- The patient is a "fit" older adult with no functional, cognitive, or social complexity identified at intake

CGA is not a substitute for specialized workup. A positive cognitive screen on MoCA or MMSE triggers neuropsychological referral; a frailty score does not replace a cardiology or oncology evaluation. The CGA functions as a coordinating framework, not an endpoint.

The distinction between CGA and a standard geriatric consultation is also clinically meaningful. A consultation addresses a specific referral question; the CGA is a systematic, domain-by-domain protocol producing a documented care plan with assigned team responsibilities and follow-up criteria. The frailty assessment and advance care planning assessment pages address two downstream products that commonly emerge from a completed CGA.

References

• American Geriatrics Society (AGS) — Clinical practice guidelines, Beers Criteria, and CGA framework endorsements
• British Geriatrics Society — Comprehensive Geriatric Assessment Toolkit
• Centers for Medicare & Medicaid Services — 42 CFR §483.20, Resident Assessment
• National Institute on Aging (NIA) — Frailty and aging research definitions
• International Society of Geriatric Oncology (SIOG) — 2021 Clinical Practice Guidelines on CGA in oncology
• Mini Nutritional Assessment (MNA) — Nestlé Nutrition Institute (public validation data)
• Montreal Cognitive Assessment (MoCA) — official scoring and norms

The law belongs to the people. Georgia v. Public.Resource.Org, 590 U.S. (2020)