IADL: Instrumental Activities of Daily Living Scale

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:

1. Ability to use the telephone, including looking up numbers and making calls
2. Shopping, managing grocery or other purchases independently
3. Food preparation, planning, preparing, and serving meals
4. Housekeeping, maintaining a home to an adequate standard
5. Laundry, washing and handling personal clothing
6. Mode of transportation, using public or private transportation independently
7. Responsibility for own medications, preparing and taking medications at correct doses and times
8. 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