3.1 Functional Assessment

Quick Answer: Function is what the patient can safely do, not the diagnosis on the problem list. Screen ADLs (Katz) and IADLs (Lawton), gait and fall risk (TUG, 30-second chair stand, fall history), senses (hearing and vision), cognition and mood (Mini-Cog, PHQ-2/9, GAD-7; MoCA or AD-8 when indicated), development and school performance in children, and caregiver strain. A positive screen changes driving, living situation, work, or sports clearance even when the ICD-10 code does not.

ANCC Domain I lists functional assessment as a distinct skill: cognitive, developmental, physical capacity, and family/caregiver roles. The exam is testing whether you treat function as data that revises risk and disposition, not as a courtesy paragraph after the 'real' physical.

ADLs versus IADLs — Katz and Lawton

Activities of daily living (ADLs) are the self-care tasks required to live inside the home without hands-on help. The Katz Index scores six: bathing, dressing, toileting, transferring, continence, and feeding. Dependence in even one ADL — especially transferring or toileting — raises fall, infection, pressure-injury, and placement risk.

Instrumental ADLs (IADLs) are the community-living tasks that keep an adult independent. The Lawton IADL Scale covers telephone use, shopping, food preparation, housekeeping, laundry, transportation, medication management, and finances. IADL loss usually precedes ADL loss. A patient who still bathes and dresses independently but can no longer manage refills or the checkbook is already functionally impaired.

Exam trap: the word 'independent' in last year's history is not a functional assessment. Ask a concrete week. Who shopped? Who set up the pillbox? Who drove you here? Who paid the rent? Collateral from a partner or adult child is part of the assessment, not gossip. Patients with early executive dysfunction often give a polished, overconfident self-report.

Physical capacity: gait, strength, and falls

Do not wait for a fracture to ask about mobility.

Timed Up and Go (TUG): rise from a chair, walk 3 meters, turn, return, and sit. CDC STEADI treats 12 seconds or longer in community-dwelling older adults as a positive fall-risk screen. Watch the quality. Hesitation, path deviation, pushing off with the arms, or a near-loss of balance is data even if the stopwatch reads 11 seconds.

30-second chair stand: arms crossed, stand and sit as many times as possible in 30 seconds. A count below the CDC STEADI age- and sex-specific norm flags lower-extremity weakness and fall risk. It is a better strength screen than 'any trouble with stairs?'

Gait speed under about 0.8 meters per second is associated with frailty, hospitalization, and mortality. You do not need a gait lab — mark 4 meters in the hallway.

Fall history is part of the functional exam. Ask about falls in the past year, near-falls, fear of falling that has already restricted activity, injuries, and whether the last fall was a clear trip or unexplained. One unexplained fall plus a gait abnormality is enough to open a multifactorial workup: orthostatic vitals, medicines (especially anticholinergics, benzodiazepines, opioids, and antihypertensives), vision, feet and footwear, home hazards, and cognition.

Hearing and vision as function

Uncorrected hearing and vision loss impersonate dementia, depression, nonadherence, and a 'poor historian.' A whispered-voice or single-question hearing screen, otoscopy, and asking about the last refraction are functional tools. A patient who stopped driving at night or no longer attends services because of hearing is already restricted. Treat sensory loss as a reversible contributor to IADL decline before you label major neurocognitive disorder.

Cognition, mood, and informant screens

Mini-Cog (3-item recall plus clock draw) is a brief primary-care screen. Scores of 0–2 are a positive screen and require a fuller evaluation — not an automatic dementia diagnosis. Do not start a cholinesterase inhibitor from a Mini-Cog alone.

MoCA is more sensitive for mild cognitive impairment. A commonly cited cutoff is below 26 out of 30, education-adjusted. Use it when the Mini-Cog is positive, the history is subtle (executive or language complaints with intact recall), or family reports a change the patient denies. Administration requires training; do not eyeball a homemade version and call it a MoCA.

AD-8 is an 8-item informant interview. It catches decline the patient minimizes. A positive informant screen with a reassuring patient interview is still a positive cognitive assessment.

PHQ-2 (anhedonia plus depressed mood) is the depression gate. A positive PHQ-2 leads to PHQ-9, review of the suicide item, and a function question: work, school, parenting, sleep, appetite. GAD-7 screens anxiety that commonly drives school avoidance, somatization, and caregiver collapse. Mood scores are functional data. A PHQ-9 of 18 with passive death wishes changes the same-day plan even if the stated chief complaint was fatigue.

Developmental surveillance, structured tools, and school function

In infants, preschoolers, and school-age children, function is development plus school participation.

Surveillance happens at every well visit: parental concern, milestone review, observation in the room, and risk factors (prematurity, hearing loss, lead, early adversity). Surveillance is not optional small talk.

Structured tools are added at recommended ages or whenever surveillance is concerning:

• ASQ-3 / ASQ:SE — parent-completed developmental and social-emotional screens across infancy and preschool.
• M-CHAT-R/F — autism screen at 18 and 24 months (usable 16–30 months), with the follow-up interview for medium-risk scores.
• Vanderbilt ADHD (or a similar validated scale) — parent and teacher ratings. A 10-minute office impression of a squirmy 8-year-old is not an ADHD assessment.

School function belongs in the history: grades, IEP or 504, suspensions, attendance, bullying, and whether homework takes three hours because of attention, reading, or anxiety. A child who meets motor milestones but is failing third-grade reading is functionally impaired.

Caregiver burden and family role strain

The identified patient may be stable only because a spouse, adult child, or grandparent is absorbing the work. The Zarit Burden Interview (full or short form) conceptually measures guilt, time, health, and financial strain. You do not have to administer the full scale on an exam vignette — you do have to ask who provides care, how many hours, whether the caregiver is missing work or sleep, and whether they are considering placement.

Role strain is bidirectional. A parent of a medically complex preschooler, a teen parenting a sibling, or a middle-aged adult sandwiched between a toddler and a parent with dementia all have functional assessments of their own. Caregiver collapse is a disposition-changing finding.

When function — not diagnosis — changes the plan

The same diagnosis produces different plans when function differs.

• Driving: unexplained syncope, a markedly prolonged TUG, a positive Mini-Cog plus family reports of near-misses, visual acuity below the state standard, or alcohol use with a prior impaired-driving event. Counsel to stop driving when safety is in doubt and know your state's reporting rules.
• Living situation: new ADL dependence without a safe caregiver is a same-day safety problem, not a 'follow up in 3 months' note.
• Work: a warehouse worker with recurrent back pain who can no longer lift is a functional, occupational, and forms problem, not only a musculoskeletal diagnosis.
• Sports clearance: concussion with persistent balance or cognitive symptoms, cardiac symptoms on the AHA 14-element history, or a single kidney or single eye in a collision sport changes clearance even if the resting exam is normal.

Frail elderly versus merely older adult

Older adult is an age band. Frail elderly is a physiologic state: decreased reserve and increased vulnerability to stressors. The Fried phenotype counts unintentional weight loss, self-reported exhaustion, weak grip, slow gait, and low activity. Three or more features = frail; one or two = prefrail. The Clinical Frailty Scale (Rockwood) is a 1–9 judgment from very fit to terminally ill that already incorporates function.

An 82-year-old who walks a mile, manages taxes, and takes two medicines is an older adult. A 74-year-old on 12 medicines, with two unexplained falls, a Mini-Cog of 1, and a daughter who now does all the cooking is frail. The second patient has a different pretest probability for delirium, adverse drug events, and failed outpatient treatment. Chronologic age alone does not make the distinction.

Tool → age → positive next step

Vignette

A 79-year-old woman is 'here for blood pressure.' She lives alone, still drives, and says she is fine. Her daughter, who scheduled the visit, reports two grocery-store near-falls, unpaid bills, and a burned pot last month. TUG is 16 seconds with a path deviation. Mini-Cog is 2 (recalls one of three words; clock numbers are clustered on one side). PHQ-2 is 3. She takes diphenhydramine for sleep.

The assessment is not 'hypertension, stable.' It is IADL loss, positive cognitive and fall screens, possible depression, and a high-risk medicine in a woman who is still driving. Today's plan must address safety (driving, home, medicines), depression, and a scheduled cognitive workup — not only a refill.