# Comprehensive Geriatric Assessment

## Introduction

Comprehensive Geriatric Assessment (CGA) is a multidimensional, interdisciplinary diagnostic process designed to determine the medical, psychological, and functional capabilities of an older person in order to develop a coordinated and integrated plan for treatment and long-term follow-up. It is fundamentally distinct from the standard medical evaluation in that it integrates assessment of functional status, cognition, mood, social support, and environmental factors alongside the traditional review of organ systems and disease states. This holistic approach recognizes that in elderly patients, the interaction between medical conditions, functional impairments, cognitive decline, and social circumstances determines clinical outcomes far more powerfully than any single diagnosis.

The evidence base supporting CGA is robust. Meta-analyses have consistently demonstrated that CGA reduces mortality (odds ratio 0.76), decreases rates of institutionalization, and slows functional decline compared to usual care. CGA is, without exaggeration, the cornerstone of geriatric medicine practice and the foundation upon which all other geriatric interventions are built. Its effectiveness derives from its systematic identification of remediable problems that would otherwise go undetected, its emphasis on patient-centered goal setting, and its reliance on interdisciplinary teamwork.

## Historical Context and Evidence Base

The origins of CGA trace to the pioneering work of Marjory Warren at West Middlesex Hospital in the 1930s and 1940s. Warren demonstrated that systematic assessment of elderly patients in chronic care wards, many of whom had been considered beyond help, led to successful rehabilitation and discharge home. Her work established the fundamental principle that comprehensive evaluation could identify treatable conditions masked by the overlay of multiple chronic diseases and functional decline.

The modern evidence base for CGA was established by Rubenstein and colleagues in their landmark 1984 randomized controlled trial of an inpatient CGA unit. This study demonstrated that structured geriatric assessment and management reduced one-year mortality from 48.3 percent to 23.8 percent and significantly reduced nursing home placement. The Ellis et al. Cochrane review, updated in 2017, confirmed that CGA in acute hospital settings resulted in patients being more likely to be alive and in their own homes at 12 months (relative risk 1.06, 95% confidence interval 1.01 to 1.10). These findings led the National Institute for Health and Care Excellence (NICE) to recommend CGA for all older adults admitted to hospital in their 2016 guidelines.

## Domains of CGA

### Medical Assessment

The medical component of CGA goes well beyond a standard problem list by requiring systematic prioritization of active diagnoses based on disease severity, prognosis, and the patient's own goals. Medication review is a central element, encompassing reconciliation of all prescribed and over-the-counter medications, assessment of appropriateness using tools such as the Beers criteria and STOPP/START criteria, evaluation of adherence, and identification of adverse drug reactions and prescribing cascades.

Nutritional status demands specific attention in elderly patients, including documentation of weight changes, body mass index calculation, appetite assessment, and formal screening with the Mini Nutritional Assessment (MNA). Vaccination status should be reviewed and updated, including influenza, pneumococcal vaccines (PCV20 or PCV15 followed by PPSV23), recombinant zoster vaccine (Shingrix), COVID-19 vaccines, and tetanus-diphtheria boosters. Preventive care decisions, including age-appropriate cancer screening and cardiovascular risk assessment, must be individualized based on life expectancy and patient preferences.

Sensory assessment encompasses both vision (using the Snellen chart for distance and dedicated near-vision testing) and hearing (beginning with the whispered voice test and referring for formal audiometry when indicated). Oral health assessment, including dental status, denture fit, and evaluation for xerostomia, is frequently overlooked but critically important for nutritional status and infection risk. Continence assessment should address both urinary and fecal incontinence, documenting onset, pattern, severity, and impact on quality of life.

### Functional Assessment

Functional assessment is arguably the most important domain of CGA because functional status is the strongest predictor of clinical outcomes in older adults. The Katz Index of Activities of Daily Living (ADLs) evaluates six basic self-care functions: bathing, dressing, toileting, transferring, continence, and feeding. The scale is scored from 0 to 6, with a well-documented hierarchical loss pattern in which bathing is typically lost first and feeding last. The Lawton-Brody Scale of Instrumental Activities of Daily Living (IADLs) assesses higher-level functions required for independent community living, including telephone use, shopping, food preparation, housekeeping, laundry, transportation, medication management, and financial management. Scored from 0 to 8, IADLs are more sensitive to early functional decline than ADLs.

Mobility assessment is a critical component of functional evaluation. Gait speed, measured over a short distance (typically 4 meters), has been called the "sixth vital sign" due to its powerful predictive value. A normal gait speed exceeds 1.0 meters per second; a speed below 0.8 m/s predicts disability, and a speed below 0.6 m/s predicts falls and mortality. The Timed Up and Go (TUG) test, which measures the time required to rise from a chair, walk 3 meters, turn, return, and sit down, identifies fall risk when it exceeds 12 seconds. The Short Physical Performance Battery (SPPB) combines balance testing, gait speed measurement, and timed chair stands into a composite score from 0 to 12, with scores below 10 predicting disability. Grip strength, measured with a Jamar dynamometer, serves as a surrogate for overall muscle strength, with values below 26 kg in men and below 18 kg in women suggesting sarcopenia according to the EWGSOP2 criteria.

| Functional/Mobility Measure | Method | Normal Value | Abnormal Cutoff | Predicts |
|-----------------------------|--------|-------------|-----------------|----------|
| Gait speed | 4-meter walk | >1.0 m/s | <0.8 m/s (disability); <0.6 m/s (falls/mortality) | Disability, hospitalization, mortality |
| Timed Up and Go (TUG) | Rise, walk 3 m, return, sit | <10 s | >12 s | Fall risk |
| SPPB | Balance + gait speed + chair stands | 10-12 | <10 | Disability |
| Grip strength | Jamar dynamometer | — | <26 kg (men); <18 kg (women) | Sarcopenia, frailty |
| Katz ADL | 6 self-care activities | 6 | Loss of ≥1 ADL | Functional dependence |
| Lawton IADL | 8 community-living activities | 8 | Loss of ≥1 IADL | Early functional decline |

<image>A comprehensive flowchart illustrating the domains and tools of Comprehensive Geriatric Assessment. Show a central hub labeled "CGA" with six major spokes radiating outward to domains: Medical, Functional, Cognitive, Psychological, Social, and Environmental. Each domain should have sub-branches listing specific assessment tools with their scoring ranges and cut-offs. For example, under Functional: ADL (Katz 0-6), IADL (Lawton 0-8), Gait Speed (>1.0 m/s normal), TUG (<12s normal), SPPB (0-12). Under Cognitive: MMSE (0-30, <24 abnormal), MoCA (0-30, <26 abnormal). Use color coding: green for normal ranges, yellow for borderline, red for impaired. Include the interdisciplinary team members associated with each domain in small icons.</image>

### Cognitive Assessment

Cognitive screening is essential in CGA because cognitive impairment profoundly affects treatment adherence, decision-making capacity, functional independence, and prognosis. The Mini-Cog, which combines a three-item recall with clock drawing, offers an excellent rapid screen that can be completed in approximately three minutes, with reported sensitivity of 76 to 99 percent and specificity of 89 to 96 percent.

The Montreal Cognitive Assessment (MoCA) is a more comprehensive 30-point instrument that tests visuospatial ability, naming, attention, language, abstraction, delayed recall, and orientation. With a cutoff of less than 26 for abnormality and an education adjustment of plus one point for individuals with 12 or fewer years of education, the MoCA is superior to the Mini-Mental State Examination (MMSE) for detecting mild cognitive impairment. The MMSE, while historically important, is limited by copyright restrictions, a ceiling effect that misses MCI, and poor sensitivity for executive dysfunction. The Saint Louis University Mental Status (SLUMS) examination is freely available and provides better detection of MCI than the MMSE.

| Cognitive Screening Tool | Time | Score Range | Abnormal Cutoff | Sensitivity | Specificity | Key Strengths |
|-------------------------|------|-------------|----------------|-------------|-------------|---------------|
| Mini-Cog | ~3 min | 0-5 | ≤2 | 76-99% | 89-96% | Rapid; minimal education bias |
| MoCA | ~10 min | 0-30 | <26 | 90-96% | 87% | Detects MCI; tests executive function |
| MMSE | ~10 min | 0-30 | <24 | 71-92% | 56-96% | Widely known; limited by copyright, ceiling effect |
| SLUMS | ~7 min | 0-30 | <27 (HS+), <25 (HS-) | Better than MMSE for MCI | — | Free; better MCI detection than MMSE |

The Clock Drawing Test screens visuospatial and executive function and can be incorporated into other instruments or used independently. Detailed neuropsychological testing is reserved for situations of diagnostic uncertainty, atypical presentations, or capacity evaluations where greater precision is needed. Importantly, delirium superimposed on dementia must always be assessed, using the Confusion Assessment Method (CAM), as this combination is common in hospitalized elderly and carries a particularly poor prognosis.

### Psychological/Psychiatric Assessment

Depression screening is a mandatory component of CGA. The PHQ-9, scored from 0 to 27, is widely used, while the Geriatric Depression Scale (GDS) offers the advantage of a yes/no format that excludes somatic symptoms overlapping with medical illness. The GDS-15 uses a cutoff of 5 or greater for possible depression, and the GDS-30 uses a cutoff of 11 or greater. Anxiety screening with the GAD-7 or the Geriatric Anxiety Inventory (GAI) addresses an often-overlooked source of suffering in elderly patients.

| Depression/Anxiety Screening Tool | Score Range | Cutoff | Format |
|----------------------------------|-------------|--------|--------|
| PHQ-9 | 0-27 | ≥10 (moderate depression) | 9 items; includes somatic symptoms |
| GDS-15 | 0-15 | ≥5 | Yes/No format; excludes somatic symptoms |
| GDS-30 | 0-30 | ≥11 | Yes/No format; excludes somatic symptoms |
| GAD-7 | 0-21 | ≥10 (moderate anxiety) | 7 items |
| Geriatric Anxiety Inventory (GAI) | 0-20 | ≥9 | Designed for older adults |

Assessment of loneliness (UCLA Loneliness Scale), caregiver burden (Zarit Burden Interview), and substance use (AUDIT-C for alcohol, review of benzodiazepine and opioid use) rounds out the psychiatric assessment. Critically, suicidal ideation must be assessed in every elderly patient screened for depression, as older white males have the highest suicide rate of any demographic group, and firearms are the most common method.

### Social Assessment

The social domain of CGA examines living situation, social network and support systems, caregiver availability and burden, financial resources and insurance coverage (including the complexities of Medicare Parts A through D, Medicaid, and supplemental coverage), and legal status with respect to advance directives, power of attorney, and guardianship. Safety concerns, including elder abuse (screened with the Elder Abuse Suspicion Index), intimate partner violence, and self-neglect, must be actively sought. Transportation access and food security are frequently unaddressed social determinants of health that directly affect medication adherence, nutritional status, and healthcare engagement.

### Environmental Assessment

Environmental assessment evaluates the physical home setting for safety hazards and barriers to independent functioning. Key elements include adequacy of lighting, floor surfaces, availability of grab bars and stair rails, bathroom modifications, and the presence of fall hazards such as loose rugs, clutter, electrical cords, pets, and uneven thresholds. The ability to access essential services, including grocery stores, pharmacies, and healthcare facilities, is assessed alongside technology needs such as emergency call systems and telephone accessibility. Adaptive equipment requirements, including reachers, raised toilet seats, shower benches, and hospital beds, are identified and addressed.

## The Interdisciplinary Team

The effectiveness of CGA depends on the coordinated efforts of an interdisciplinary team, each member bringing unique expertise to the assessment and management plan. The geriatrician provides medical assessment, care coordination, and overall direction of the care plan. The nurse manages medications, wound care, patient education, and care coordination. The social worker conducts psychosocial assessment, navigates community resources, manages discharge planning, and facilitates family meetings. Physical therapists assess mobility and provide strength training, gait training, and fall prevention programs. Occupational therapists evaluate ADL and IADL function, conduct home safety assessments, and recommend adaptive equipment.

The pharmacist performs medication reconciliation, identifies drug interactions, and makes deprescribing recommendations. The psychologist or neuropsychologist conducts cognitive testing and provides behavioral interventions. The speech-language pathologist evaluates swallowing function and communication disorders. The dietitian assesses nutritional status and implements dietary interventions. The chaplain or spiritual care provider addresses spiritual needs and existential distress that may profoundly affect treatment decisions and quality of life.

Regular interdisciplinary team meetings, shared care plans, and documentation of agreed-upon goals are essential for the team to function effectively. The team must communicate not only within itself but also with the patient, family, and other providers outside the team.

<image>A circular diagram showing the interdisciplinary CGA team centered around the patient and family. Show the patient and a family caregiver in the center, surrounded by team members in a ring: geriatrician, nurse, social worker, physical therapist, occupational therapist, pharmacist, psychologist, speech pathologist, dietitian, and chaplain. Each team member should have labeled arrows pointing to their specific assessment domains and interventions. Use a second outer ring showing the settings where CGA occurs: inpatient acute care, outpatient clinic, rehabilitation unit, home-based, and long-term care. Include bidirectional communication arrows between all team members to emphasize collaboration.</image>

## Settings for CGA

### Inpatient CGA

Acute Care for Elders (ACE) units represent a dedicated approach to inpatient CGA, featuring environmental modifications designed for elderly patients, daily interdisciplinary rounds, early mobilization protocols, and an unwavering focus on preserving function. The evidence supports ACE units in reducing functional decline at discharge, decreasing delirium incidence, and achieving these benefits without increasing length of stay. Geriatric consultation services offer an alternative model in which geriatric specialists provide recommendations to non-geriatric wards, though the effectiveness of this approach depends heavily on the implementation of recommendations, which occurs in only 50 to 70 percent of cases. Perioperative CGA, as demonstrated in the POPS trial (Proactive Care of Older People Undergoing Surgery), has been shown to reduce postoperative delirium, complications, and length of stay.

### Outpatient CGA

Geriatric assessment clinics represent the most common model for CGA of community-dwelling elderly patients. The time-intensive nature of CGA, which typically requires 60 to 90 minutes for an initial assessment, limits the number of patients who can be evaluated in a traditional clinic schedule. Follow-up is essential, as the assessment is only as valuable as the implementation of its recommendations and subsequent reassessment. In geriatric oncology, CGA predicts chemotherapy toxicity more accurately than oncologist judgment or performance status alone, as demonstrated by Hurria and colleagues in 2011, making it an indispensable tool for treatment decision-making.

### Home-Based CGA

Home-based assessment offers the unique advantage of direct environmental evaluation and the opportunity to observe functional performance in the patient's actual living environment rather than in the artificial setting of a clinic or hospital. The Independence at Home demonstration project under Medicare showed that home-based primary care reduced hospitalizations and costs. Hospital at Home programs, which deliver acute-level care in the patient's residence for selected diagnoses, represent an extension of this concept that is gaining traction as an alternative to traditional inpatient care.

## CGA-Based Interventions and Outcomes

### Evidence for Effectiveness

The evidence supporting CGA is among the strongest in geriatric medicine. The Stuck et al. meta-analysis of 1993 demonstrated that CGA reduces mortality by 35 percent in inpatient geriatric units. CGA-guided interventions have been shown to reduce mortality with a number needed to treat of approximately 20 at 12 months in hospitalized elderly, decrease nursing home admission with a similar number needed to treat, slow functional decline, reduce hospital readmission rates, and decrease medication-related problems. CGA has also been demonstrated to be cost-effective in acute hospital settings, as shown by Eamer and colleagues in 2017.

### Goal-Directed Care Planning

The ultimate purpose of CGA is to generate a care plan that is aligned with the patient's own priorities and values. This requires identifying what matters most to the patient, setting realistic, measurable, and time-bound goals, and ensuring that all interventions support rather than conflict with those goals. The Patient Priorities Care framework, developed by Tinetti and colleagues, provides a structured approach for aligning care with what matters most to the patient, shifting the focus from disease-specific guideline adherence to patient-centered outcome optimization. Regular reassessment and goal modification are essential as the patient's condition and priorities evolve over time.

<image>A before-and-after clinical vignette diagram showing the impact of CGA. On the left side ("Before CGA"), show a complex elderly patient with multiple unaddressed problems depicted as overlapping circles: polypharmacy (12 medications), undiagnosed cognitive impairment, fall risk, depression, social isolation, and inappropriate cancer screening. On the right side ("After CGA"), show the same patient with organized, prioritized interventions: deprescribed to 7 medications, cognitive diagnosis established with safety plan, home modifications completed, antidepressant started, community resources connected, and screening decisions aligned with goals. Use a central arrow labeled "CGA Process" connecting the two sides, with the interdisciplinary team shown along the arrow.</image>

## Barriers and Limitations

Despite its proven effectiveness, CGA faces significant barriers to widespread implementation. The time-intensive nature of the process limits throughput in fee-for-service payment models that inadequately compensate for the extended time required. The Medicare Annual Wellness Visit (AWV) partially addresses this gap but is not a full CGA. Relevant CPT codes include 99483 for cognitive assessment and care planning, and G0438 and G0439 for initial and subsequent AWVs.

A critical workforce shortage undermines the scalability of CGA, with approximately 7,000 certified geriatricians in the United States serving a population of over 55 million adults aged 65 and older. The implementation gap, in which CGA recommendations are identified but not fully carried out, further limits effectiveness. Technology integration, including electronic CGA tools and telemedicine-based assessment platforms, offers potential solutions for improving access and efficiency.

## Key Clinical Pearls

- CGA is the single most evidence-supported intervention in geriatric medicine — it reduces mortality, institutionalization, and functional decline
- Gait speed is the "sixth vital sign" — a single measure of walking speed (<0.8 m/s) predicts disability, hospitalization, and mortality as well as complex multivariable models
- Always use CGA before making major treatment decisions in older adults — oncology, surgery, cardiac interventions
- The Mini-Cog (3-item recall + clock draw) is the best brief cognitive screen for busy clinical settings — it takes 3 minutes and has excellent sensitivity
- CGA is only effective if recommendations are actually implemented and followed up — the assessment alone is not sufficient
- Patient priorities (what matters most to the patient) should drive the care plan, not disease-specific guidelines

## References
1. Ellis G, Gardner M, Tsiachristas A, et al. Comprehensive geriatric assessment for older adults admitted to hospital. *Cochrane Database Syst Rev*. 2017;9:CD006211.
2. Stuck AE, Siu AL, Wieland GD, Adams J, Rubenstein LZ. Comprehensive geriatric assessment: a meta-analysis of controlled trials. *Lancet*. 1993;342(8878):1032-1036.
3. Tinetti ME, Costello DM, Naik AD, et al. Outcome goals and health care preferences of older adults with multiple chronic conditions. *JAMA Intern Med*. 2021;181(10):1298-1305.
4. Hurria A, Togawa K, Mohile SG, et al. Predicting chemotherapy toxicity in older adults with cancer: a prospective multicenter study. *J Clin Oncol*. 2011;29(25):3457-3465.
5. Rubenstein LZ, Josephson KR, Wieland GD, English PA, Sayre JA, Kane RL. Effectiveness of a geriatric evaluation unit: a randomized clinical trial. *N Engl J Med*. 1984;311(26):1664-1670.