Tools of Functional Assessment

Functional assessment measures what a person actually does in daily life, not merely what diseases they have. Tools exist to make this measurement standardised, reproducible and comparable across settings.

Purpose of using standardised tools: they allow information exchange between acute, rehabilitation and community settings, permit measurement of effectiveness, foster comparison of treatments, and minimise repeated collection of identical information by different team members.

Three levels of measurement (ICF, 2001): impairment (body function or structure), activity limitation (difficulty executing a task), and participation restriction (problems in involvement in life situations). Different tools address different levels.

Three functional core measures in CGA: frailty, basic ADLs, and IADLs. The hierarchy rule determines which to use — severely ADL-dependent patients are not tested for frailty; robust patients are not tested for basic ADLs.

Two methods of data capture: report (by the patient or a proxy — tells you what they do under real living conditions) and performance testing (tells you what they can do under standard conditions). Discrepancies between the two are common and informative.

Katz Index (1963) — six items: bathing, dressing, toileting, transferring, continence, feeding. Graded independent/dependent, letters A to G. The classic hierarchy of ADL loss.

Barthel Index (1965; modified 1988) — ten items: feeding, bathing, grooming, dressing, bowels, bladder, toilet use, transfer, mobility, stairs. Scored 0–100 (or 0–20). It is an observation of what the patient does, and is the RCP/BGS-endorsed ADL scale, but has a ceiling effect in ambulatory patients.

Lawton Physical Self-Maintenance Scale (PSMS, 1969) — six items: toileting, feeding, dressing, grooming, physical ambulation, bathing. Each graded on five levels, dichotomised to a total of 0–6 (6 = independent). Published in the same paper as the Lawton IADL scale.

Lawton IADL scale (1969) — eight items: telephone, shopping, food preparation, housekeeping, laundry, transport, medications, finances. IADLs need "instruments," and are the first functions to be lost.

OARS Multidimensional Functional Assessment Questionnaire — assesses IADLs alongside social and economic resources; widely used in surveys.

Clinical rule: if difficulty is reported, always ask "how does she manage?" — is the task neglected, or is someone else doing it? Mobility, Gait and Balance Tools (high-yield numbers)

Gait speed over a 4-metre track: below 0.6 m/s is abnormal; 0.6–0.8 m/s is high-risk. Each 0.1 m/s fall in gait speed equals a 7% rise in fall risk.

Timed Get-Up-and-Go (Mathias, Nayak and Isaacs, 1986): more than 12 seconds indicates high fall risk (sensitivity 77%, positive predictive value 93% in the community).

Tinetti Performance-Oriented Mobility Assessment (1986): 14 tasks, score below 24 out of 28 indicates fall risk; takes 10–15 minutes.

Short Physical Performance Battery (SPPB): combines gait speed, 30-second chair stand and the 4-stage balance test (each position held 10 seconds). Berg Balance Scale: 14 items, 0–56 (0–20 wheelchair-bound, 21–40 walks with assistance, 41–56 independent).

Functional Independence Measure (FIM) — scores 18 functions across self-care, sphincter control, mobility, locomotion, communication and social cognition; the standard rehabilitation outcome measure.

RCP/BGS endorsed scales (Table 98.3): ADL — Barthel Index; vision, hearing and communication — Lambeth Disability Screening Questionnaire; memory — Abbreviated Mental Test (10 items); depression — Geriatric Depression Scale (30-item, 15-item short form); morale — Philadelphia Geriatric Center Morale Scale.

Other domain tools (Table 96.1): nutrition — Mini Nutritional Assessment (MNA), SNAQ; special senses — whispered voice test, Hearing Handicap Inventory, Snellen chart; oral health — GOHAI; social network — Lubben Social Network Scale; cognition — MMSE; mood — GDS, Zung.

Frailty tools: Fried phenotype (weight loss, exhaustion, weakness, slow gait, low activity); FRAIL scale (Fatigue, Resistance, Aerobic, Illnesses more than 5, Loss of weight 5%) — answerable in 15–30 seconds; SOF index (weight loss, cannot rise from chair 5 times without arms, reduced energy); Clinical Frailty Scale (9 points, seconds to apply); Frailty Index (30 or more deficits, continuous 0–1).

Screening questions usable at the bedside: "Do you need help at home?" (function) · "Do you have trouble walking or lose your balance? Have you had a fall? Are you afraid of falling?" (mobility) · "Are you sad?" (mood) · "Have you lost weight?" (nutrition) · "Are you on seven or more medicines?" (polypharmacy) · "Do you wet yourself?" (continence).

WHO ICOPE — from deficit to capacity. The ICOPE 5-step pathway (screen, assess, intervene, follow up, community engagement) screens six domains — mobility, cognition, vitality/nutrition, vision, hearing and psychological well-being — either by a professional or by self-assessment through the ICOPE Monitor app. Step-2 tools are named explicitly: SPPB for mobility; Mini-Cog, MoCA, MMSE or GPCOG for cognition; MNA, DETERMINE, MUST or SNAQ65+ for nutrition; PHQ-9 for mood; pure tone and speech audiometry for hearing.

Minimum data sets are now mandated. The German S3 guideline (2024) requires six core dimensions in at least 15 minutes; the Italian guideline (2024) recommends the Multidimensional Prognostic Index (MPI) for prognosis; ASCO 2023 mandates the Practical Geriatric Assessment (PGA) in oncology. The trend is domain-mandated but tool-agnostic.

Gait speed is being repositioned as the single best functional marker. A 2025 Age and Ageing study of about 3,600 older adults found that among all components of frailty and sarcopenia, low physical performance (slow gait speed) was the best single predictor of incident basic and instrumental ADL disability; sarcopenia as a whole construct was not associated with increased disability risk. EWGSOP2 defines low physical performance as gait speed of 0.8 m/s or less.

Automated and digital tools. The electronic frailty index (eFI2) is replacing the original eFI in English primary care from 2025, allowing population-level functional risk stratification from routine records. mHealth and wearable-based functional assessment gives objective, quantitative data in place of subjective observer-rated scales, but a 2024 systematic review found high risk of bias and minimal integration into daily practice.

Diagnostic accuracy data for screening instruments. In emergency-department settings, seven screens pooled across 1,663 participants gave sensitivity 0.85 and specificity 0.77 against full CGA; PRISMA-7 was the most sensitive (0.84–0.98) and the Clinical Frailty Scale the most specific, both with AUROC around 0.90.

Indian use. LASI applies Katz-type ADL and Lawton-type IADL items; grip strength was the most discriminant frailty component in Indian men (79.1%) and physical activity in women (81.6%). AWGS (not EWGSOP2) cut-offs should be used for sarcopenia-related functional measures in Indians, and BIA rather than DXA is the practical mass-measurement modality.