A functional assessment for dementia measures whether cognitive problems interfere with everyday independence; it is useful but cannot diagnose dementia by itself. In one study, a common questionnaire reached 84.7% test-set accuracy; Medicare patients generally owe 20% after the Part B deductible, and concerning changes should prompt a broader evaluation. The distinction matters because dementia disrupts independent daily activities, while mild cognitive impairment, or MCI, does not necessarily do so. Functional assessment helps clarify that difference by examining what a person actually manages at home.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- What does a functional assessment measure?
- How accurate is it?
- What are the limits?
- What does the assessment cost?
- What should you do next?
What does a functional assessment measure?
The assessment covers instrumental activities of daily living, known as IADLs, and basic activities of daily living, or BADLs. IADLs include shopping, cooking, and household chores. BADLs include washing, eating, and dressing. IADL problems usually appear earlier.
Someone may still dress and eat independently but struggle to shop or prepare a familiar meal. Loss of basic self-care is more noticeable in moderate-to-advanced disease. The evaluator needs more than a simple yes-or-no answer. The important question is whether the person completes each task independently or now needs reminders, supervision, or direct help.
How accurate is it?
A study of 1,801 participants examined the Functional Activities Questionnaire, or FAQ. A score of 6 or higher distinguished very mild Alzheimer's disease from MCI with 80.3% sensitivity, 87% specificity, and 84.7% test-set accuracy. In plain language, the cutoff identified many—but not all—participants with very mild Alzheimer's disease.
It also correctly separated most—but not all—participants with MCI. These results describe one research cohort and one comparison, not a guarantee for every patient. The overlap shows why the score cannot stand alone. In the study, 14.5% of participants with MCI scored at or above 6, while 18.5% of those with Alzheimer's disease scored below 6.
What are the limits?
A functional score shows the extent of difficulty, but not necessarily its cause. Stroke, infection, depression, medication effects, and other conditions can produce symptoms that resemble dementia. The National Institute on Aging says diagnosis requires a broader evaluation of cognition, medications, medical and psychiatric causes, laboratory findings, and sometimes imaging or biomarkers. Functional findings are one part of that evidence.
Routine screening also differs from evaluating a recognized problem. The U.S. Preventive Services Task Force considers the evidence insufficient to determine the benefits and harms of screening asymptomatic, community-dwelling adults aged 65 or older. It advises clinicians to evaluate symptoms once they are recognized.
What does the assessment cost?
Medicare Part B covers a separate cognitive-assessment and care-planning visit to establish or confirm dementia. Beneficiaries generally pay 20% of the Medicare-approved amount after meeting the Part B deductible, so coverage does not necessarily mean a free visit. Medicare's CPT 99483 service typically involves 50 minutes of face-to-face care. It requires assessment of basic and instrumental daily activities, an independent historian, dementia staging, safety and caregiver evaluation, and a written care plan.
Functional decline can also increase unpaid care demands. The Alzheimer's Association reports that each decrease in an ADL or IADL is associated with nearly five additional caregiving hours per month. It valued U.S. unpaid dementia care at $446.3 billion in 2025.
What should you do next?
Prepare concrete examples before the appointment. Specific changes are more useful than saying that someone is "less independent." A borderline or reassuring score should not end the evaluation when real-life decline is continuing. Likewise, a high score does not prove dementia until the clinician considers cognition and other possible causes.
- Note which tasks have changed, such as shopping, cooking, washing, eating, or dressing.
- Record whether the person needs reminders, supervision, or hands-on help.
- Bring a current medication list for the broader clinical review.
- Ask someone familiar with the person's daily abilities to attend or provide information.
- Request discussion of dementia stage, safety concerns, caregiver needs, and the written care plan.
