IADL: Instrumental Activities of Daily Living Scale
An 8-item clinician-rated or self-report scale assessing functional independence in complex daily activities such as managing finances, medication, transportation, and housekeeping. Originally developed by Lawton & Brody (1969) for older adult populations.
About the IADL
The Instrumental Activities of Daily Living (IADL) Scale was developed by M. Powell Lawton and Elaine M. Brody at the Philadelphia Geriatric Center in 1969 as part of a broader effort to comprehensively assess functioning in older adults. It remains one of the most widely used measures of functional status in geriatric and neuropsychological assessment.
The IADL is distinguished from the Basic Activities of Daily Living (ADL) scale by its focus on higher-order, complex activities that require cognitive and organizational capacity. These are activities that are typically affected earlier in the course of cognitive decline than basic self-care tasks such as bathing or dressing.
What the Assessment Measures
The IADL assesses eight domains of instrumental functioning:
- Ability to use the telephone, including looking up numbers and making calls
- Shopping, managing grocery or other purchases independently
- Food preparation, planning, preparing, and serving meals
- Housekeeping, maintaining a home to an adequate standard
- Laundry, washing and handling personal clothing
- Mode of transportation, using public or private transportation independently
- Responsibility for own medications, preparing and taking medications at correct doses and times
- Ability to handle finances, managing bank accounts, paying bills, budgeting
Scoring
Each item is scored on a graded scale reflecting degree of independence, typically 0 (dependent) to 1 (independent) per item in the standard binary scoring, yielding a total score range of 0–8.
- Score of 8: Fully independent in all instrumental activities
- Score 5–7: Mild limitations; may require minimal support
- Score 3–4: Moderate limitations; consistent support required
- Score 0–2: Severe limitations; substantial supervision or care required
Some versions use multi-level scoring (0–2 or 0–3 per item) for more granular assessment.
Notes on Scoring and Gender
Lawton and Brody's original scale was designed with different item applicability based on gender (reflecting societal norms of the 1960s). Contemporary usage applies all 8 items regardless of gender, and clinicians should interpret results in the context of the client's premorbid functional role and capabilities.
Clinical Applications
The IADL is used across multiple settings:
- Geriatric assessment: Baseline and monitoring for dementia, MCI, and age-related functional decline
- Neuropsychological evaluation: As a functional outcome measure alongside cognitive testing
- Discharge planning: Hospital and rehabilitation settings to assess readiness for independent living
- Mental health: Monitoring functional impact of depression, anxiety, or psychotic disorders in older adults
Psychometric Properties
- Excellent inter-rater reliability when administered by trained clinicians
- Adequate internal consistency across diverse populations
- Strong convergent validity with cognitive measures and clinician-rated global assessments
- Sensitive to functional decline in early dementia stages
- Validated cross-culturally across numerous languages and settings (Tafiadis et al., 2023; Siriwardhana et al., 2018; Kelbling et al., 2024)
Clinical Considerations
- The IADL reflects current functional status and may be influenced by physical health, motivation, or environmental factors beyond cognitive capacity
- Discrepancy between self-reported and informant-reported scores is clinically meaningful, informants often identify deficits that patients minimize
- For patients with dementia, informant report is recommended as primary data source
References
- Lawton MP, Brody EM. (1969). Assessment of older people: self-maintaining and instrumental activities of daily living. The Gerontologist, 9(3), 179–186.
- Tafiadis D, Siafaka V, Voniati L, et al. (2023). Lawton's Instrumental Activities of Daily Living for Greek-Speaking Adults with Cognitive Impairment: A Psychometric Evaluation Study. Brain Sciences, 13(7), 1087. PMID: 37509023
- Siriwardhana DD, Walters K, Rait G, et al. (2018). Cross-cultural adaptation and psychometric evaluation of the Sinhala version of Lawton Instrumental Activities of Daily Living Scale. PLoS One, 13(6), e0199820. PMID: 29953501
- Kelbling E, Ferreira Prescott D, Shearer M, et al. (2024). An assessment of the content and properties of extended and instrumental activities of daily living scales: a systematic review. Disability and Rehabilitation, 46(10), 1968–1985. PMID: 37415395
Frequently Asked Questions
Is the IADL self-report or clinician-administered?
The IADL can be administered as a clinician interview, a self-report questionnaire, or an informant-report completed by a family member or caregiver. In populations with cognitive impairment or dementia, informant report is recommended as the primary data source, because affected individuals may lack insight into their functional difficulties.
What does a low IADL score mean?
Because the IADL is scored in the direction of independence (8 = fully independent, 0 = dependent in all domains), a lower score reflects greater functional limitation. Scores in the range of 0–2 indicate severe difficulty requiring substantial support across most instrumental activities. Clinicians interpret scores alongside the individual's premorbid functioning, physical health, and living situation.
Can the IADL diagnose dementia?
No. The IADL is a functional screen, not a diagnostic instrument. It identifies limitations in complex daily activities that may signal cognitive decline, but a diagnosis of dementia requires a comprehensive clinical evaluation including cognitive testing, medical history, and clinical judgement.
How many items does the IADL have, and what does each one assess?
The IADL contains 8 items covering telephone use, shopping, food preparation, housekeeping, laundry, transportation, medication management, and financial management. Each item is typically scored 0 (dependent) or 1 (independent), yielding a total range of 0–8. Some extended versions use multi-level scoring (0–2 or 0–3 per item) for more detailed assessment.
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