Functional Autonomy Measurement System (SMAF)

Abstract

The Functional Autonomy Measurement System (SMAF) is a globally recognized, clinical-based instrument designed to measure the level of functional dependency, disabilities, and handicaps, particularly in older people. Developed by Hébert in 1984 and subsequently revised, the SMAF assesses 29 functional items grouped into five main domains, providing a comprehensive profile of an individual’s autonomy needs.

Unlike scales that focus solely on performance, the SMAF emphasizes the degree of required assistance, making it highly valuable for planning care services and resource allocation in healthcare settings and long-term care facilities. The scoring system assigns a disability level ranging from 0 (independent) to -3 (dependent) for each item, allowing for precise quantification of support needs.

Keywords

SMAF, Functional Autonomy, Activities of Daily Living, Instrumental Activities of Daily Living, Geriatrics, Functional Assessment, Dependency, Disability, Long-term Care.

Authors

Hébert, R., Carrier, R., Bilodeau, A., Buodeau, A., Desrosiers, J., Dubuc, N.

Purpose

The primary purpose of the SMAF is to provide a standardized, reliable method for quantifying an individual’s functional status and the resulting level of dependency. This measurement is crucial for clinical decision-making, epidemiological research, and effective management of care resources, especially within the field of gerontology and Geriatrics.

Initially developed to measure handicaps, the scale allows professionals to determine the specific amount of assistance an individual requires across various physical and mental tasks. This detailed assessment helps tailor intervention plans, thereby optimizing the quality and cost-effectiveness of long-term care services.

Construct

The SMAF measures the construct of Functional Autonomy, which is defined by an individual’s ability to perform essential daily activities without assistance. This construct is broken down into five distinct categories encompassing physical, cognitive, and social functioning, aligning broadly with the World Health Organization’s (WHO) framework of disability.

The scale systematically translates observed functional limitations into measurable dependency scores, distinguishing between independence, difficulty, need for supervision, need for partial help, and total dependence. This granular approach ensures that the assessment captures the complex reality of functional impairment in aging or disabled populations.

Validity

Early validation studies, such as those conducted by Hébert et al. (1988), established the SMAF as a robust instrument for measuring handicaps. The scale demonstrates strong construct validity, as its structure aligns logically with established domains of functional independence, including Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL).

Furthermore, the SMAF has been shown to possess excellent criterion validity, correlating strongly with other established measures of functional status and dependency. Its capacity to predict the utilization of healthcare resources and need for formal assistance further confirms its utility in clinical and administrative contexts.

Reliability

The SMAF exhibits high levels of inter-rater reliability, which is critical for an observational scale used across various clinical settings. Desrosiers et al. (1995) specifically investigated the reliability of the revised SMAF for epidemiological research, confirming its stability and consistency across different assessors.

The consistent 5-level scoring system (0 to -3) for 29 items ensures standardized interpretation, contributing significantly to its overall reliability. The clear behavioral anchors provided for each score level minimize subjective judgment by the observer, strengthening the scale’s dependability in longitudinal studies and comparative analyses.

Factor Analysis

Factor analysis of the SMAF typically confirms the five underlying dimensions of functional autonomy. These dimensions represent distinct facets of dependency: Activities of Daily Living (ADL), Mobility, Communication, Mental Functions, and Instrumental Activities of Daily Living (IADL).

In 2003, Pinsonnault et al. confirmed the utility of the structure and proposed the development of a dedicated social subscale, demonstrating the instrument’s adaptability and ongoing refinement to capture a broader spectrum of autonomy needs beyond strictly physical limitations. The clear factor structure supports its use as a multi-dimensional assessment tool.

Instrument

Test Type: Observational rating scale, clinical assessment instrument.

Format: 29 items, scored on a 5-point disability scale (0 to -3).

Language Available: Primarily French (original) and English (translations widely available).

Population Group: Clinical populations requiring functional assessment, particularly older adults, those with chronic illnesses, or those undergoing rehabilitation.

Age Group: Adults and Geriatric populations.

Population Details: Used extensively in long-term care settings, hospitals, and community care services to measure functional capacity and quantify care requirements for individuals with varying degrees of disabilities.

Test Methodology: Typically administered by trained healthcare professionals (nurses, occupational therapists, physicians) based on observation and/or interview with the patient or a reliable proxy caregiver.

Keywords

Assessment Scale, Rehabilitation, Long-term Care, Functional Status, Hébert, Dependency Score, Gerontology, ADL, IADL.

Authors

Author ORCID Identifier: Information not provided in source content.

Affiliation Email addresses: Information not provided in source content.

Correspondence Address: Information not provided in source content.

Permissions & Fee and Test Year

The SMAF was initially introduced in 1984, with major revisions occurring in 1993 and 2001 (Hébert et al.). Information regarding specific commercial permissions and licensing fees is not detailed in the source material, but the scale is widely utilized in public health systems.

The instrument is publicly available for review, and the original PDF documentation can be downloaded here: www.a4ebm.org/sites/default/files/Measuring%20Health.pdf

Reference’s

Desrosiers, J., Bravo, G., Hébert, R., & Dubuc, N., A. (1995). Reliability of the Revised Functional Autonomy Measurement System (SMAF) for Epidemiological Research. Age and Ageing, 24:402-406.

Hébert, R., Carrier, R., & Buodeau, A. (1984). Le système de mesure de l’autonomie fonctionnelle: description d’un instrument de mesure des handicaps. In W. Van Eimeren, R. Engelbrecht, & C.D. Fiagle (Eds.), Third International Conference on System Science in Health Care (pp.241-244). Berlin: Springer-Verlag.

Hébert, R., Carrier, R., & Bilodeau, A. (1988). The Functional Autonomy Measurement System (SMAF): description and validation of an instrument for the measurement of handicaps. Age and Ageing, 17(5), 293-302.

Hébert, R., Guilbault, J., Desrosiers, J., & Dubuc, N. (2001). The functional autonomy measurement system (SMAF): A clinical-based instrument for measuring disabilities and handicaps in older people. Geriatrics Today: Journal of Canadian Geriatric Society, Sept. 2001, 1-7.

McDowell, Ian. (2006). Measuring Health: A Guide to Rating Scales and Questionnaires, Third Edition. OXFORD UNIVERSITY PRESS.

Pinsonnault, E., Desrosiers, J., Dubuc, N., Kalfat, H., Colvez, A., & Delli-Colli, N. (2003). Functional autonomy measurement system: development of a social subscale. Archives of Gerontology and Geriatrics, 37, 223-233.

Items of the Functional Autonomy Measurement System (SMAF)

Scoring/Interpretation: For each item, the disability is scored on a 5-level scale: 0 (independent), -0.5 (with difficulty), -1 (needs supervision), -2 (needs help), -3 (dependent) (Hebert et al., 2001).

A. ACTIVITIES OF DAILY LIVING (ADL)

1. FEEDS SELF
   • Feeds self independently
   • With difficulty
   • Feeds self but needs stimulation or supervision OR food must be prepared or cut or puréed first
   • Needs some help to eat OR dishes must be presented one after another
   • Must be fed totally by another person OR has a naso-gastric tube or a gastrostomy

   naso-gastric, tube gastrostomy

2. WASHING
   • Washes self independently (including getting in or out of the bathtub or shower)
   • With difficulty
   • Washes self but needs cueing, OR needs supervision, OR needs preparation, OR needs help for the complete weekly bath, only (including washing feet and hair)
   • Needs help for the daily wash but participates actively
   • Must be washed by another person
3. DRESSING (all seasons)
   • Dresses self independently
   • With difficulty
   • Dresses self but needs cueing, OR needs supervision, OR clothing must be readied and presented, OR needs help for finishing touches (buttons, laces)
   • Needs help dressing
   • Must be dressed by another person

   support hose/stocking

4. GROOMING

   (brushes teeth or combs hair or shaves or trims finger or toenails or puts on make-up)

   • Grooms self independently
   • With difficulty
   • Grooms self but needs cueing or supervision
   • Needs help for grooming
   • Must be groomed by another person
5. URINARY FUNCTION
   • Normal voiding
   • Occasional incontinence, OR dribbling, OR needs frequent cueing to avoid incontinence
   • Frequent urinary incontinence
   • Complete urinary incontinence, OR wears a diaper or an indwelling catheter or a urinary condom

   diaper, indwelling catheter, urinary condom

   day incontinence, night incontinence

6. BOWEL FUNCTION
   • Normal bowel function
   • Occasional incontinence, OR needs cleansing enema occasionally
   • Frequent incontinence, OR needs cleansing enema regularly
   • Always incontinent, OR wears a diaper or an ostomy

   diaper, ostomy

   day incontinence, night incontinence

7. TOILETTING
   • Toilets self (including getting on/off toilet, wiping self and managing clothing)
   • With difficulty
   • Needs supervision for toileting, OR uses commode, bedpan or urinal
   • Needs help to go to the toilet, OR use commode, bedpan or urinal
   • Does not use toilet, commode, bedpan or urinal

   commode, bedpan, urinal

B. MOBILITY

1. TRANSFERS (bed to chair or wheelchair and to stand, and vice-versa)
   • Gets in and out of bed or chair alone
   • With difficulty
   • Gets in and out of bed/chair alone but needs cueing, supervision or guidance specify: ______________________________________
   • Needs help to get in and out of bed/chair specify: ______________________________________
   • Bedridden (must be lifted in and out of bed)

   particular positioning: lift, transfer board

2. WALKING INSIDE (including in the building and going to the elevator)
   • Walks independently (with or without cane, prosthesis, orthosis or walker)
   • With difficulty
   • Walks independently but needs guidance, cueing or supervision in certain circumstances OR unsafe gait
   • Needs help of another person to walk
   • Does not walk

   cane, tripod, quadripod, walker

   *Distance of at least 10 meters

3. DONNING PROSTHESIS OR ORTHOSIS
   • Does not wear prosthesis or orthosis
   • Dons prosthesis or orthosis independently
   • With difficulty
   • Donning of prosthesis of orthosis needs checking, OR needs partial help
   • Prosthesis or orthosis must be put on by another person Type of prosthesis or orthosis:
4. PROPELLING A WHEELCHAIR (W/C) INSIDE
   • Does not need a wheelchair
   • Propels wheelchair independently
   • With difficulty
   • Needs to have wheelchair pushed
   • Unable to use wheelchair (must be transported on stretcher)

   standard wheelchair

   wheelchair with unilateral axis

   motorized wheelchair

   three wheeled scooter

   four wheeled scooter

5. NEGOTIATING STAIRS
   • Goes up and down stairs independently
   • With difficulty
   • Requires cueing, supervision or guidance to negotiate stairs OR does not safely negotiate stairs
   • Needs help to go up and down stairs
   • Does not negotiate stairs
6. MOVING AROUND OUTSIDE
   • Walks independently (with or without cane, prosthesis, orthosis or walker)
   • With difficulty
   • Uses a wheelchair or scooter independently W/C with difficulty OR walks independently but needs guidance, cueing, or supervision in certain circumstances, OR unsafe gait1
   • Needs help of another person to walk1, OR to use W/C
   • Cannot move around outside (must be transported on a stretcher)

   1 Distance of at least 20 meters

C. COMMUNICATION

1. VISION
   • Sees adequately with or without corrective lenses
   • Visual problems but sees enough to do ADLs
   • Only sees outlines of objects and needs guidance in ADLs
   • Blind

   corrective lenses, magnifying glass

2. HEARING
   • Hears adequately with or without hearing aid
   • Hears if spoken to in a loud voice, OR needs hearing aid put in by another person
   • Only hears shouting or certain words, OR reads lips, OR understands gestures
   • Completely deaf and unable to understand what is said to him/her

   hearing aid

3. SPEAKING
   • Speaks normally
   • Has a speech/language problem but able to express him/herself
   • Has a major speech/language problem but able to express basic needs OR answer simple questions (yes, no) OR uses sign language
   • Does not communicate technical aid: computer communication board

D. MENTAL FUNCTIONS

1. MEMORY
   • Normal memory
   • Minor recent memory deficit (names, appointments, etc.) but remembers important facts
   • Serious memory lapses (shut off stove, medications, putting things away, eating, visitors)
   • Almost total memory loss or amnesia
2. ORIENTATION
   • Oriented to time, place and persons
   • Sometimes disoriented to time, place and persons
   • Only oriented for immediate events (i.e., time of day) and in the usual living environment and with familiar persons
   • Complete disorientation
3. COMPREHENSION
   • Understands instructions and requests
   • Slow to understand instructions and requests
   • Partial understanding even after repeated instructions OR is incapable of learning
   • Does not understand what goes on around him/her
4. JUDGMENT
   • Evaluates situations and makes sound decisions
   • Evaluates situations but needs help in making sound decisions
   • Poorly evaluates situations and only makes sound decisions with strong suggestions
   • Does not evaluate situations and dependent on others for decision making
5. BEHAVIOUR
   • Appropriate behaviour
   • Minor behavioural problems (whimpering, emotional lability, stubbornness, apathy) requiring occasional supervision or a reminder or stimulation
   • Major behavioural problems requiring more intensive supervision (aggressive towards self or others, disturbs others, wanders, screams out constantly)
   • Dangerous, requires restraint OR harmful to others or self-destructive OR tries to run away

E. INSTRUMENTAL ACTIVITIES OF DAILY LIVING

1. HOUSEKEEPING
   • Does housekeeping alone (including daily housework and occasional big jobs)
   • With difficulty
   • Does housekeeping but needs supervision or cueing to ensure cleanliness (including washing the dishes) OR needs help for big jobs (floors, windows, painting, lawn, clearing the snow, etc.)
   • Needs help for daily housework
   • Does not do housework
2. MEAL PREPARATION
   • Prepares own meals independently
   • With difficulty
   • Prepares meals but needs cueing to maintain adequate nutrition
   • Only prepares light meals OR heats up pre-prepared meals (including handling the plates)
   • Does not prepare meal
3. SHOPPING
   • Plans and does shopping independently (food, clothes)
   • With difficulty
   • Plans and shops independently but needs delivery service
   • Needs help to plan or shop
   • Does not shop
4. LAUNDRY
   • Does all laundry independently
   • With difficulty
   • Does laundry but needs cueing or supervision to maintain standards of cleanliness
   • Needs help to do laundry
   • Does not do laundry
5. TELEPHONE
   • Uses telephone independently (including use of directory)
   • With difficulty
   • Answers telephone but only dials a few memorized numbers or emergency numbers
   • Communicates by telephone but does not dial numbers or lift the receiver off the hook
   • Does not use the telephone
6. TRANSPORTATION
   • Able to use transportation alone (car, adapted vehicle, taxi, bus, etc.)
   • With difficulty
   • Must be accompanied to use transportation OR uses paratransit independently
   • Uses car or paratransit only if accompanied and has help getting in and out of the vehicle
   • Must be transported on a stretcher
7. MEDICATION USE
   • Takes medication according to prescription OR does not need medication
   • With difficulty
   • Needs weekly supervision (including supervision by telephone) to ensure compliance to prescription OR uses a medication dispenser aid (prepared by someone else)
   • Takes medication if prepared daily
   • Must be given each dosage of medications (as prescribed) medication dispenser aid
8. BUDGETING
   • Manages budget independently (including banking)
   • With difficulty
   • Needs help for certain major transactions
   • Needs help for some regular transactions (cashing checks, paying bills) but uses pocket money wisely
   • Does not manage budget