2.3 Functional Assessment (Katz ADL / Lawton IADL) & Frailty Syndromes
Key Takeaways
- Functional status is the single strongest predictor of morbidity, hospitalization, nursing home placement, and mortality in older adults, superseding chronological age and disease count.
- The Katz Index evaluates 6 basic Activities of Daily Living (ADLs: Bathing, Dressing, Toileting, Transferring, Continence, Feeding); functional loss follows a predictable hierarchy with bathing lost first and feeding lost last.
- The Lawton-Brody Scale evaluates 8 Instrumental Activities of Daily Living (IADLs); deficits in complex tasks (finances, medication management) serve as sensitive early indicators of cognitive impairment and executive dysfunction.
- The Fried Frailty Phenotype identifies clinical frailty through 5 operational criteria: unintentional weight loss, exhaustion, low physical activity, slow gait speed, and muscle weakness (≥3 criteria = Frail; 1-2 = Pre-frail).
- The Timed Up and Go (TUG) test objectively quantifies mobility and fall risk; a completion time of ≥12 seconds indicates high fall risk requiring a comprehensive multifactorial fall evaluation (CDC STEADI).
Functional Assessment (Katz ADL / Lawton IADL) & Frailty Syndromes
In adult-gerontology primary care, functional status is recognized as the "6th vital sign." While disease-specific management remains important, an older adult's ability to execute self-care activities and live independently in the community dictates their quality of life, healthcare utilization, and survival. Functional decline is often the initial manifestation of acute illness, occult malignancy, or cognitive impairment.
1. The Hierarchy of Functional Assessment
Functional ability spans a hierarchical continuum of complexity across three tiers:
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| HIERARCHICAL CONTINUUM OF HUMAN FUNCTION |
| |
| [TIER 3: ADVANCED ACTIVITIES OF DAILY LIVING (AADLs)] |
| - Complex vocational, societal, recreational, and occupational roles (e.g., employment, civic |
| volunteering, international travel, operating a business, playing complex sports). |
| - Lost first in early functional vulnerability. |
| | |
| v |
| [TIER 2: INSTRUMENTAL ACTIVITIES OF DAILY LIVING (IADLs) - Lawton-Brody] |
| - Complex activities necessary for independent community living (e.g., managing finances, |
| managing medications, telephone use, shopping, meal preparation, housekeeping). |
| - Highly sensitive to executive dysfunction, early mild cognitive impairment, and delirium. |
| | |
| v |
| [TIER 1: BASIC ACTIVITIES OF DAILY LIVING (ADLs) - Katz Index] |
| - Fundamental self-care tasks essential for biological survival (Bathing, Dressing, Toileting, |
| Transferring, Continence, Feeding). |
| - Lost in severe, advanced disease or late-stage dementia. |
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2. Basic Activities of Daily Living (ADLs): The Katz Index
The Katz Index of Independence in Activities of Daily Living assesses functional independence across 6 basic domains. Each domain is scored dichotomously as 1 (Independent) or 0 (Dependent):
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| KATZ INDEX OF INDEPENDENCE IN BASIC ADLs |
| |
| DOMAIN INDEPENDENCE (1 POINT) DEPENDENCE (0 POINTS) |
| =========== ==================================== ===================================== |
| 1. BATHING Bathes self completely or needs help Needs assistance with more than one |
| cleaning only a single body part. body part, or needs help getting in/out.|
| --------------------------------------------------------------------------------------------- |
| 2. DRESSING Picks out clothes and dresses self Needs assistance with tying shoes or |
| completely without human assistance. requires total physical dressing help. |
| --------------------------------------------------------------------------------------------- |
| 3. TOILETING Gets to toilet, gets on/off, cleans Uses bedpan/commode or requires total |
| self, and adjusts clothing independently. human assistance to use toilet. |
| --------------------------------------------------------------------------------------------- |
| 4. TRANSFERRING Moves in and out of bed/chair without Requires human assistance or mechanical |
| human assistance (can use cane/walker). lift to transfer from bed or chair. |
| --------------------------------------------------------------------------------------------- |
| 5. CONTINENCE Exercises complete voluntary control Has occasional/frequent accidents or |
| over urination and defecation. requires catheter/incontinence briefs. |
| --------------------------------------------------------------------------------------------- |
| 6. FEEDING Gets food from plate into mouth Requires human assistance to eat, or |
| without help (cutting meat allowed). depends on tube feeding / total TPN. |
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Scoring Interpretation & The Hierarchical Rule
- Score 6/6: Full basic functional independence.
- Score 4/6: Moderate functional impairment (typically requires structured home care services).
- Score $\le 2/6$: Severe functional dependence (indicates need for 24-hour skilled nursing facility or comprehensive custodial care).
3. Instrumental Activities of Daily Living (IADLs): The Lawton-Brody Scale
The Lawton-Brody IADL Scale evaluates 8 complex domains necessary for autonomous community living. It is scored from 0 (Low function, dependent) to 8 (High function, independent):
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| LAWTON-BRODY INSTRUMENTAL ADL ASSESSMENT |
| |
| 1. Ability to Use Telephone - Operates phone independently, dials known numbers (1 pt) |
| 2. Shopping - Takes care of all shopping needs independently (1 pt) |
| 3. Food Preparation - Plans, prepares, and serves adequate meals independently (1 pt) |
| 4. Housekeeping - Maintains house alone or with occasional heavy work (1 pt) |
| 5. Laundry - Does personal laundry completely independently (1 pt) |
| 6. Mode of Transportation - Travels independently on public transit or drives car (1 pt) |
| 7. Responsibility for Meds - Takes correct medications at correct dosages/times (1 pt) |
| 8. Ability to Handle Finances- Manages financial matters, writes checks, pays bills (1 pt) |
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High-Yield Clinical Pearls for IADLs:
- Early Dementia Detection: The inability to manage finances (e.g., bounced checks, falling victim to financial scams) and medication management errors (e.g., duplicate dosing, missed refills) are the earliest functional manifestations of Alzheimer's disease and vascular dementia.
- When an older adult presents with unexplained weight loss or worsening diabetic control, always evaluate IADL domains #2 (Shopping), #3 (Food Preparation), and #7 (Medication Management) before ordering invasive diagnostic testing.
4. Objective Mobility & Fall Risk Stratification
Falls are the leading cause of fatal and non-fatal injury in older adults. Approximately 30% of community-dwelling adults $>65$ fall each year. The CDC STEADI (Stopping Elderly Accidents, Deaths, & Injuries) initiative provides a standardized evaluation algorithm:
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| CDC STEADI THREE-QUESTION SCREENING ALGORITHM |
| |
| Ask every older adult annually: |
| 1. Have you fallen in the past year? |
| 2. Do you feel unsteady when standing or walking? |
| 3. Do you worry about falling? |
| | |
| [IF YES TO ANY OF THE 3 QUESTIONS -> HIGH RISK] |
| | |
| v |
| [EXECUTE OBJECTIVE FUNCTIONAL MOBILITY TESTS] |
| - Timed Up and Go (TUG) Test |
| - 30-Second Chair Stand Test (evaluates lower body muscle power) |
| - 4-Stage Balance Test (side-by-side, semi-tandem, full tandem, single-leg stand) |
| | |
| v |
| [MULTIFACTORIAL FALL INTERVENTION PLAN] |
| - Deprescribe high-risk Beers medications (sedatives, anticholinergics, antihypertensives) |
| - Physical Therapy referral for balance/gait training (Tai Chi, strength training) |
| - Vitamin D supplementation (if deficient) |
| - Correct visual impairment (cataract extraction; avoid multifocal lenses while walking) |
| - Formal home safety occupational therapy evaluation |
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The Timed Up and Go (TUG) Test Protocol
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| TIMED UP AND GO (TUG) TEST PROTOCOL |
| |
| 1. Patient sits comfortably in a standard armchair (seat height ~46 cm), back against chair. |
| 2. Mark a line on the floor exactly 3 meters (10 feet) away. |
| 3. Instruct patient: "When I say 'Go', stand up, walk to the line at your normal pace, |
| turn around, walk back to the chair, and sit down." |
| 4. Start stopwatch on "Go"; stop timing when patient's buttocks touch the chair seat. |
| |
| [INTERPRETATION THRESHOLDS] |
| - < 10 Seconds: Completely Normal / Freely Mobile / Low Fall Risk |
| - 10-11 Seconds: Borderline Mobility / Normal for Frail Elderly |
| - >= 12 Seconds: ABNORMAL / High Fall Risk -> Triggers Comprehensive Multifactorial Assessment |
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5. Frailty Syndromes: Pathophysiology and Clinical Models
Frailty is a biological syndrome of decreased physiological reserve and resistance to stressors, resulting from cumulative multisystem decline. It creates extreme vulnerability to disproportionate functional deterioration following minor stressor events (e.g., a mild UTI triggering profound delirium, immobility, and permanent functional loss).
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| PATHOPHYSIOLOGY OF THE FRAILTY CYCLE |
| |
| +-------------------------------------------------------------------------------------------+ |
| | Chronic Inflammation ("Inflammaging": Elevated IL-6, TNF-alpha, CRP) + Endocrine Senescence| |
| +-------------------------------------------------------------------------------------------+ |
| | |
| v |
| +-------------------------------------------------------------------------------------------+ |
| | Sarcopenia (Loss of Muscle Mass & Quality) <---------> Anorexia of Aging / Malnutrition | |
| +-------------------------------------------------------------------------------------------+ |
| | |
| v |
| +-------------------------------------------------------------------------------------------+ |
| | Decreased Resting Metabolic Rate & Total Energy Expenditure | |
| +-------------------------------------------------------------------------------------------+ |
| | |
| v |
| +-------------------------------------------------------------------------------------------+ |
| | Chronic Fatigue / Exhaustion -> Severe Physical Inactivity -> Further Muscle Wasting | |
| +-------------------------------------------------------------------------------------------+ |
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The Fried Frailty Phenotype (Cardiovascular Health Study Criteria)
The Fried model operationalizes frailty using 5 distinct, measurable criteria:
| Frailty Phenotype Criterion | Operational Clinical Definition | Diagnostic Measurement Tool |
|---|---|---|
| 1. Unintentional Weight Loss | Loss of $>10\text{ lbs}$ (or $>5%$ of baseline body weight) in the preceding 12 months. | Scale weight verification / clinical history. |
| 2. Self-Reported Exhaustion | Feeling that "everything I did was an effort" or "I could not get going" on $\ge 3$ days/week. | Center for Epidemiological Studies Depression (CES-D) scale items. |
| 3. Muscle Weakness | Grip strength in the lowest 20% quintile stratified by sex and BMI. | Handheld dynamometer (dominant hand). |
| 4. Slow Walking Speed | Walking time over 15 feet in the slowest 20% quintile stratified by sex and standing height. | 15-foot timed gait speed test (speed $<0.8\text{ m/sec}$). |
| 5. Low Physical Activity | Physical energy expenditure in lowest 20% ($<383\text{ kcal/wk}$ for men; $<270\text{ kcal/wk}$ for women). | Minnesota Leisure Time Physical Activity Questionnaire. |
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| FRIED FRAILTY STAGING & CLINICAL ACTIONS |
| |
| CRITERIA MET FRAILTY STAGE CLINICAL MANAGEMENT STRATEGY |
| ============ ============= =================================================== |
| 0 Criteria ROBUST Primary prevention, routine health screening, |
| regular aerobic and resistance exercise. |
| --------------------------------------------------------------------------------------------- |
| 1 - 2 Criteria PRE-FRAIL Targeted secondary prevention: Progressive resistance |
| training, dietary protein (1.2-1.5 g/kg/d), Vitamin D.|
| --------------------------------------------------------------------------------------------- |
| >= 3 Criteria FRAIL Multimodal comprehensive geriatric assessment, |
| rigorous deprescribing, fall hazard mitigation, |
| advance care planning, caregiver support. |
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6. Sarcopenia Evaluation and Management
Sarcopenia is the progressive, generalized skeletal muscle disorder involving the loss of muscle mass, muscle strength, and physical performance. It is a core driver of physical frailty.
EWGSOP2 Diagnostic Algorithm
- Screening: Administer the SARC-F questionnaire (Scores 0–10 evaluating Strength, Assistance walking, Rising from a chair, Climbing stairs, and Falls). A score $\ge 4$ predicts sarcopenia.
- Assessment of Muscle Strength (Probable Sarcopenia):
- Grip strength: $<27\text{ kg}$ in men; $<16\text{ kg}$ in women.
- Chair stand test: $>15\text{ seconds}$ for 5 unassisted chair rises.
- Confirmation of Muscle Quantity/Quality (Confirmed Sarcopenia):
- Dual-Energy X-ray Absorptiometry (DXA) or Bioelectrical Impedance Analysis (BIA) demonstrating low Appendicular Skeletal Muscle Mass (ASM).
- Severity Stratification (Severe Sarcopenia):
- Gait speed $\le 0.8\text{ m/sec}$ on a 4-meter walk test, or TUG $\ge 20\text{ seconds}$.
Evidence-Based Interventions for Sarcopenia:
- High-Intensity Progressive Resistance Training (PRT): 2–3 sessions per week; the single most effective intervention to stimulate muscle protein synthesis and type II fiber hypertrophy.
- Dietary Protein Optimization: $1.2\text{ to }1.5\text{ g/kg/day}$ of high-quality protein divided evenly across meals ($25\text{--}30\text{ g}$ leucine-rich protein per meal), unless contraindicated by severe end-stage CKD (eGFR $<30\text{ mL/min}$ not on dialysis).
- Vitamin D Repletion: Maintain serum 25-hydroxyvitamin D levels $>30\text{ ng/mL}$.
7. Environmental Assessment & Caregiver Strain
A. Home Safety Fall Hazard Checklist
- Flooring: Remove all throw/scatter rugs; ensure wall-to-wall carpeting is tacked down; eliminate clutter and exposed electrical cords.
- Lighting: Install 100-watt equivalent glare-free LED lighting; nightlights in hallways, bedrooms, and bathrooms; accessible bedside light switches.
- Bathrooms: Install securely anchored grab bars inside the shower/tub stall and adjacent to the toilet (towel racks must never be used as grab bars); non-skid rubber adhesive strips in the tub; raised toilet seat; walk-in shower bench.
- Stairways: Sturdy, continuous bilateral handrails extending past the top and bottom steps; brightly contrasting non-skid tape on step edges.
- Footwear: Recommend non-skid, thin-soled, closed-heel supportive shoes; advise against walking in socks or smooth-soled slippers.
B. Caregiver Strain & Burnout Assessment
Informal family caregivers provide $>80%$ of long-term care for community-dwelling frail older adults. Unrecognized caregiver burnout leads to elder neglect, physical illness, and premature nursing home placement.
- Modified Caregiver Strain Index (MCSI): A 13-item validated tool evaluating financial, physical, psychological, and social strain. Items include employment disruptions, sleep interruptions, and emotional confinement.
- Zarit Burden Interview (ZBI): Gold-standard 22-item instrument (scores $\ge 21$ indicate significant caregiver burden).
- Clinical Interventions for Caregiver Strain: Link family to local Area Agencies on Aging (AAA), adult day health centers, in-home respite services, disease-specific support groups (e.g., Alzheimer's Association), and formal palliative care consultation.
An 80-year-old community-dwelling male with mild vascular cognitive impairment is accompanied to the clinic by his son. The son reports that his father lives alone, continues to bathe, dress, and feed himself independently, and maintains urinary continence. However, over the past 4 months, the father has accumulated over $2,000 in unpaid utility bills, repeatedly forgotten to refill his antihypertensive medications, and sustained a minor fender-bender while driving to the grocery store. Physical examination is non-focal. Based on functional assessment principles, how should the AGPCNP categorize the patient's functional status?
A 78-year-old female presents to the primary care clinic for an annual health review. Over the past 9 months, she has experienced an unintentional 14-lb weight loss (representing 9% of her baseline body weight). On the CES-D questionnaire, she endorses that 'everything I do is a major effort' on 5 days out of every week. A handheld dynamometer evaluation reveals a dominant hand grip strength of 14 kg (lowest 20th percentile for her BMI), and her 15-foot timed walk speed is 0.65 m/sec (lowest 20th percentile). Her physical activity level is minimal. How should the AGPCNP classify her status using the Fried Frailty Phenotype criteria?
An AGPCNP is performing a fall risk assessment on an 81-year-old male who reports feeling unsteady when standing up from his living room recliner. The NP conducts a Timed Up and Go (TUG) test. The patient rises from the standard armchair using his hands to push off, walks the 3-meter distance, turns around slowly with an unsteady wide-based gait, walks back, and sits down. The total elapsed time on the stopwatch is 16 seconds. According to the CDC STEADI guidelines, what is the correct interpretation and required next clinical step?