14.1 Comprehensive Geriatric Assessment & Frailty
Key Takeaways
- Principles of the geriatric assessment is a separately enumerated blueprint subsection.
- Functional status is measured with activities of daily living and instrumental activities of daily living, which are more predictive of outcomes than diagnosis counts.
- Frailty is a distinct syndrome of reduced physiologic reserve that predicts falls, disability, hospitalization and mortality independent of comorbidity.
- Resistance exercise and adequate protein intake are the interventions with the best evidence for frailty and sarcopenia.
- Screening for geriatric syndromes should be periodic and structured, because patients rarely volunteer falls, incontinence or cognitive change.
Geriatric medicine requires a paradigm shift from single-disease pathophysiology to holistic, multidimensional assessment. The physiological decline of aging is characterized by homeostenosis—the progressive constriction of physiological reserve across organ systems—rendering older adults exceptionally susceptible to functional disability, iatrogenic injury, and multi-organ decompensation from minor physiological stressors.
1. Comprehensive Geriatric Assessment (CGA) & Functional Domains
The Comprehensive Geriatric Assessment (CGA) is an evidence-based, multidimensional, interprofessional diagnostic and therapeutic process designed to determine an older adult's medical, psychosocial, and functional capabilities, culminating in an integrated, coordinated plan for treatment and long-term follow-up.
The Core Domains of CGA
- Medical / Physical Health: Chronic multimorbidity, polypharmacy, nutritional status, sensory deficits (vision, hearing), dentition, pain, and fall history.
- Functional Status: Quantitative performance of basic and instrumental daily living skills.
- Cognitive & Mental Health: Screening for cognitive impairment, delirium risk, depression (Geriatric Depression Scale [GDS-15]), and anxiety.
- Socio-Environmental Circumstances: Caregiver network, social support, physical living environment safety, financial resources, and transportation access.
- Advance Care Planning: Values, healthcare proxy designation, and goal-concordant medical preferences.
Functional Stratification: ADLs vs. IADLs
Functional status is the single most powerful predictor of hospitalization, nursing home placement, and 1-year mortality in older adults—often far outweighing chronological age or specific disease diagnoses.
| Functional Domain | Classification Instrument | Specific Component Activities | Clinical Significance & Failure Sequence |
|---|---|---|---|
| Activities of Daily Living (ADLs) | Katz Index of ADLs | 1. Bathing (washing body in tub/shower)<br/>2. Dressing (selecting and putting on clothes/fasteners)<br/>3. Toileting (getting to commode, cleaning self)<br/>4. Transferring (moving between bed and chair)<br/>5. Continence (complete bowel and bladder control)<br/>6. Feeding (getting food from plate into mouth) | Fundamental self-care tasks essential for basic survival.<br/>Failure Sequence: Bathing and dressing typically fail first; feeding is the most resilient and fails last in advanced dementia/frailty.<br/>Loss of >=1 ADL requires direct human caregiving assistance. |
| Instrumental Activities of Daily Living (IADLs) | Lawton-Brody IADL Scale | 1. Managing Medications (taking correct pills/dosages on time)<br/>2. Managing Finances (paying bills, balancing checkbook)<br/>3. Using the Telephone (dialing, answering calls)<br/>4. Shopping for Groceries / Essentials<br/>5. Preparing Food / Meal Planning<br/>6. Housekeeping (cleaning, routine maintenance)<br/>7. Doing Laundry<br/>8. Transportation (driving, navigating public transit) | Complex organizational tasks required for independent community living.<br/>Failure Sequence: IADLs depend heavily on executive function and short-term memory; IADL deficits precede ADL deficits and represent the clinical hallmark distinguishing Mild Cognitive Impairment from early Dementia. |
2. Frailty: Phenotypic Model & Clinical Implications
Frailty is a clinical biological syndrome characterized by decreased physiological reserve and diminished resistance to stressors, resulting from cumulative, multi-system physiological dysregulation (endocrine, immune, neuromuscular, cardiovascular). Frail older adults experience disproportionate functional collapse following minor insults (e.g., uncomplicated urinary tract infection, mild dehydration, elective surgery).
Fried Phenotypic Criteria for Frailty
The Fried criteria (Cardiovascular Health Study) define frailty using 5 standardized phenotypic domains:
- Unintentional Weight Loss: Loss of >10 lbs (>4.5 kg) or >5% of baseline body weight in the preceding 12 months.
- Self-Reported Exhaustion: Positive response on the Center for Epidemiological Studies Depression (CES-D) scale to "I felt that everything I did was an effort" or "I could not get going" for >=3 days in the past week.
- Weakness (Low Grip Strength): Dominant hand grip strength measured by isometric dynamometer in the lowest 20% of the population (stratified by gender and body mass index [BMI]; typically <29-32 kg for men, <17-20 kg for women).
- Slow Walking Speed (Sluggish Gait): Time required to walk 4 meters (15 feet) in the lowest 20% of the population (gait speed < 0.8 meters/second).
- Low Physical Activity: Caloric expenditure on the Minnesota Leisure Time Activities questionnaire in the lowest 20% (<383 kcal/week for men, <270 kcal/week for women).
Diagnostic Scoring & Triage
- Robust / Non-Frail: 0 criteria met.
- Pre-Frail: 1 or 2 criteria met (high risk of progressing to full frailty; target for preventive multicomponent exercise and nutritional therapy).
- Frail: >= 3 criteria met.
ABIM Board Pearl: Frailty is NOT synonymous with multimorbidity or advanced chronological age. A frail patient undergoing elective major surgery (e.g., total hip arthroplasty, CABG) has a 4-fold higher risk of 30-day postoperative complications, prolonged institutionalization, delirium, and mortality compared to a non-frail patient of identical age and comorbidities. Preoperative frailty assessment is mandatory for risk stratification.