Is AD8 appropriate for patients who live alone without a regular informant?

AD8 is not appropriate when no reliable informant is available. Patients who live alone, have minimal social contact, or whose only potential informants have infrequent contact (e.g., adult children who visit monthly) cannot provide valid AD8 data. For these patients: rely on direct cognitive testing (MMSE, MoCA, neuropsychological battery), clinical observation over multiple visits, review of longitudinal medical records, and any collateral information from healthcare providers (home care workers, pharmacists, general practitioners). Document the absence of a reliable informant and the consequent limitation in cognitive screening.

What is the evidence base for AD8?

AD8 was developed by Galvin JE et al. and initially validated against CDR and clinical diagnosis in memory clinic populations at Washington University (Neurology 2005): sensitivity 84.6%, specificity 86.1% at cutoff 2 or above for CDR 0.5 or above. Subsequent validation studies across primary care, emergency department, and community settings have consistently demonstrated sensitivity 80-90% and specificity 80-90% across diverse settings and populations.

How does AD8 perform for detecting mild cognitive impairment (MCI)?

AD8 for MCI (CDR 0.5) detection: sensitivity approximately 85%, specificity approximately 73-80% at cutoff 2 or above in memory clinic validation studies. For very early MCI (CDR 0.5 with MMSE above 24), AD8 sensitivity drops to approximately 72-78% — as expected for a brief screen for the mildest forms of impairment. AD8 of 2 or above in MCI indicates the informant has observed meaningful change; this is clinically important for MCI counseling, follow-up scheduling, and biomarker testing decisions.

Can AD8 track treatment response or disease progression over time?

AD8 was designed primarily as a screening tool rather than a longitudinal change measure. Unlike IQCODE or CDR-SB (designed for serial monitoring), the AD8's Yes/No change response format does not provide interval-change sensitivity. Serial AD8 administration (at 6-12 month intervals) can document whether informant-observed changes are increasing (more items scored 'Yes, a change') over time. However, for treatment response monitoring in clinical trials or clinical practice, CDR-SB or IQCODE serial scoring is preferred.

Online Medical Tools — AD8 Screen

Printed on 9/4/2026

For informational purposes only. This is not medical advice.

Geriatrics

AD8 Screen

The AD8 is a brief informant-based cognitive screening interview focused on perceived change in memory, judgment, orientation, and daily cognitive function. Each endorsed change item scores 1 point (total 0-8). A score of 2 or higher is a commonly used threshold for cognitive impairment signal.

Formula: AD8 total = count of endorsed change items (0-8).

AD8 total score

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How It Works

Select an informant and administer the 8-item AD8 interview

The AD8 (Alzheimer's Disease 8) is a brief informant-based screening tool consisting of 8 questions about changes in cognitive function and everyday activities. Select an informant who knows the patient well and has regular contact — typically a spouse, adult child, or close friend. The informant is asked to compare the patient's current functioning to their functioning a few years ago (not necessarily a fixed 10-year reference like IQCODE). For each of the 8 items, the informant answers: Yes, a change (score 1); No, no change (score 0); or I don't know (score 0). The 8 items cover: memory changes (judgment problems, memory loss — including forgetting dates), orientation problems (repeating questions or stories in a short period), forgetting the correct year or month, difficulty managing finances or balancing accounts, difficulty remembering appointments/medications, and problems thinking and reasoning.

Calculate the AD8 total score (0-8)

AD8 total score = sum of items answered 'Yes, a change' (0-8 total). Items answered 'No, no change' or 'I don't know' score 0. The AD8 is specifically designed for rapid informant-based screening — total administration time is typically 3-5 minutes. It can be administered as a brief structured interview by a clinician or nurse, or completed as a self-administered questionnaire by the informant in the waiting room before a clinic visit. The AD8 was developed at Washington University in St. Louis and validated against CDR, MMSE, and clinical dementia diagnosis.

Interpret AD8 score and integrate with clinical assessment

AD8 score interpretation: 0-1 = No significant cognitive impairment signal from informant perspective — does not exclude early dementia, but informant has observed no or minimal change. 2 or above = Positive screen for possible cognitive impairment — trigger formal cognitive assessment. The AD8 cutoff of 2 or above achieves sensitivity approximately 85% and specificity approximately 86% for clinical dementia (CDR 0.5 or above) in validation studies. An AD8-positive result (2 or above) in a clinic setting should trigger: brief cognitive assessment (MMSE or MoCA), functional assessment, review of medications, laboratory workup (CBC, CMP, TSH, B12), and follow-up appointment with comprehensive cognitive evaluation if indicated.

Who Uses the AD8 Screen

Primary Care and Annual Wellness Visit Cognitive Screening

Primary care physicians, family medicine practitioners, internists, practice nurses

The AD8's 3-5 minute informant administration makes it one of the most practical tools for busy primary care settings. In the CMS Annual Wellness Visit (AWV), cognitive impairment detection is a required component. Providing the AD8 questionnaire to accompanying family members or caregivers in the waiting room, before the physician enters, generates validated cognitive screening data without requiring additional physician time. AD8 of 2 or above alerts the physician to address cognitive concerns in the visit and schedule a comprehensive cognitive evaluation.

Memory Clinic Pre-Screening and Triage

Memory clinic nurses, intake coordinators, geriatric psychiatry intake teams

AD8 administered at memory clinic intake (completed by the accompanying family member while the patient completes self-report measures) provides rapid pre-screening data before the formal evaluation. AD8 score patterns provide initial triage information: AD8 of 0-1 in a patient referred for 'memory concerns' suggests the referring clinician or patient's subjective concerns may outpace informant-observed functional changes (low likelihood of significant dementia). AD8 of 4 or above with high informant agreement suggests a high likelihood of clinically significant cognitive impairment requiring urgent comprehensive assessment.

Emergency Department Cognitive Screening

Emergency physicians, emergency nurses, hospital-based geriatric triage teams

Cognitive impairment is common in older adult emergency department (ED) presentations and frequently unrecognized. When a family member or caregiver accompanies a patient to the ED, rapid AD8 administration provides valuable baseline cognitive data. AD8 of 2 or above in an ED presentation suggests pre-existing cognitive impairment — important context for: medication choices, consent discussions, delirium superimposition evaluation, and discharge planning. ED nursing triage protocols increasingly include brief cognitive screening for older adults using tools like AD8.

Nursing Home Admission Cognitive Baseline

Nursing home nurses, MDS coordinators, nursing home physicians

AD8 administered to a family member at nursing home admission provides a rapid informant-based cognitive baseline to complement BIMS direct assessment. This is particularly valuable when the patient is admitted during delirium or acute medical illness (when BIMS underestimates baseline cognitive function). AD8 results document whether the resident had pre-existing cognitive impairment before admission — informing care planning, BPSD management approach, and communication strategies.

Alzheimer's Disease and Dementia Research Screening

Clinical researchers, Alzheimer's disease prevention trials, population health researchers

AD8 is widely used in Alzheimer's disease research for rapid pre-screening of potential study participants. Its brief administration allows telephone or online pre-screening before in-person evaluation. AD8 of 2 or above triggers in-person cognitive assessment for potential dementia cases in prevalence studies or clinical trial eligibility screening. The Washington University (Galvin et al.) validation in multiple populations supports AD8 use across diverse demographic groups in research settings.

Community Dementia Case Finding Programs

Public health teams, community health workers, Alzheimer's disease advocacy organizations

AD8 can be administered by trained non-clinical community health workers in community settings — senior centers, health fairs, community events. Its simple binary Yes/No format for informants makes it accessible for administration by lay health workers. Community AD8 screening programs using telephone interviews have demonstrated feasibility for early dementia case finding in community populations. AD8 of 2 or above in a community screening context triggers referral to primary care or memory clinic for formal evaluation.

Pro Tips

Administer AD8 before the clinic visit — waiting room completion is a practical approach

One of the most efficient AD8 administration strategies is providing the questionnaire to accompanying family members or caregivers in the waiting room before the clinic visit. This generates informant data without requiring physician time for administration. Practice staff can provide the AD8 questionnaire at check-in when an accompanying person is present. The completed AD8 is available when the physician enters, enabling targeted cognitive assessment within the routine visit flow.

The AD8 captures recent change — it is not anchored to a fixed time point

Unlike IQCODE (which anchors to 10 years ago), the AD8 asks the informant to compare current functioning to 'a few years ago.' This flexible recent reference period means AD8 is sensitive to relatively rapid changes (over months to years) that might be missed by IQCODE's 10-year anchor. The AD8 is therefore particularly useful for detecting more recent-onset cognitive changes. However, this also means a recently identified change in a patient with long-standing prior cognitive impairment may not fully reflect the entire disease history.

AD8 of 2 or above is a screening threshold — not a diagnosis

A positive AD8 (2 or above) indicates the informant has observed significant cognitive changes warranting clinical evaluation. It does not diagnose dementia, Alzheimer's disease, or any specific cognitive disorder. Many conditions can produce a positive AD8: Alzheimer's disease, vascular dementia, other dementias, depression, medication effects, thyroid disorder, B12 deficiency. A positive AD8 always requires formal medical evaluation, not automatic dementia diagnosis or treatment initiation.

AD8 self-completion by patients shows systematically lower scores than informant version

Studies comparing AD8 informant version to patient self-completion version show that patients score themselves significantly lower (fewer 'Yes, a change' responses) than informants score them — reflecting anosognosia (reduced insight) in cognitive impairment. Patient self-completion of AD8 has substantially lower sensitivity for dementia detection (~65%) compared to informant completion (~85%). When possible, always administer AD8 to an informant rather than the patient. When no informant is available, document the source and interpret a patient-completed AD8 with understanding that it will likely underestimate the degree of cognitive change.

Combine AD8 with brief direct cognitive testing for optimal sensitivity-specificity balance

The combination of AD8 (informant-based) and a brief direct cognitive test (Mini-Cog, MMSE, or MoCA) achieves higher sensitivity and specificity for dementia detection than either tool alone. When both AD8 (2 or above) and Mini-Cog (3 or below) are positive, the positive predictive value for dementia is approximately 90%. When AD8 is positive but Mini-Cog is normal, the discordance warrants clinical judgment — informant may be observing early functional decline before performance-based test impairment becomes evident.

High AD8 scores (6-8) suggest urgent evaluation — don't defer

While any AD8 of 2 or above triggers formal assessment, an AD8 of 6-8 suggests widespread, significant informant-observed cognitive and functional decline consistent with moderate-to-severe dementia. High AD8 scores trigger more urgent evaluation: same-day or next-available memory clinic appointment, immediate safety assessment (driving, cooking, medication management, financial vulnerability), and family/carer support activation. AD8 of 6 or above combined with concerning clinical presentation warrants urgent geriatric consultation.

Common Questions About Your Results

GPCOG: Both GP-assessed patient and informant components; slightly longer (~5 minutes total); validated for primary care; comparable sensitivity/specificity to AD8. Mini-Cog: Direct patient test only (3 minutes); no informant component; may miss patients with anosognosia who perform normally on brief testing; excellent for primary care but cannot substitute for informant information. IQCODE-16: More comprehensive informant assessment (16 items, 10-year anchor); higher information yield but longer (~10 minutes); better for comprehensive geriatric assessment than rapid screening. AD8: Fastest informant screen (3-5 minutes, 8 items); pragmatic for primary care; can be waiting-room self-completed by informant. Each tool has specific strengths — choice depends on available informants, time constraints, and clinical context.

AD8 detects cognitive impairment but does not distinguish dementia subtypes. The 8 items (judgment, memory, repeating stories, finances, orientation) reflect global cognitive-functional change common to all dementia types. AD8 has been validated against a combined dementia endpoint (CDR 0.5 or above for any cause) rather than Alzheimer's disease specifically. Post-screening subtype differentiation requires comprehensive evaluation including neuroimaging, neuropsychological testing, and in some cases biomarker testing (amyloid PET, CSF analysis).

Discordance between informant AD8 (positive, 2 or above) and patient self-report (denies any problems) is common in dementia due to anosognosia (reduced insight). Clinical interpretation: informant-positive AD8 with patient denial is more likely to reflect true cognitive impairment than to reflect informant inaccuracy — anosognosia is highly prevalent in Alzheimer's disease. Clinician-observed direct cognitive assessment helps resolve discordance: formal cognitive testing (MMSE, MoCA) with impaired results confirms informant's observations despite patient denial.

AD8 has been translated and validated in multiple languages including Spanish, Chinese (Mandarin and Cantonese), Japanese, Korean, Portuguese, French, German, Italian, Dutch, and Vietnamese. Cross-cultural validation studies show consistent sensitivity (~80-88%) and specificity (~80-87%) across language adaptations. The Washington University Memory and Aging Project provides access to validated translations. When using AD8 in non-English-speaking populations, use the culturally validated version rather than an informal translation.

Evidence-Based Methodology

AD8 was developed as a rapid informant interview to detect very mild dementia and is widely used with a >=2 screening threshold.

Clinical Content Trust

Last reviewed:: April 21, 2026
Guideline version:: General evidence framework v2026.04
Source set version:: Primary-source set v1

How to Interpret Your Result

Higher AD8 scores indicate stronger informant-reported cognitive decline signal and support further diagnostic assessment.

When to Use This Tool

Use when a reliable informant is available and quick screening for possible cognitive impairment is needed in primary or specialist care.

Limitations

Performance depends on informant quality and may be influenced by limited contact, stress, or baseline expectations.

For related assessments, see IQCODE-16, CDR Global and SLUMS Score.

Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.

Sources

Changelog

April 21, 2026 · trust-baseline
Clinical trust metadata enabled for this tool page with structured review/version fields.

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Frequently Asked Questions

The AD8 (Alzheimer's Disease 8) is a brief, validated 8-item informant-based screening tool for detecting early dementia. An informant (family member or close friend) rates whether they have noticed a change in the patient across 8 cognitive and functional areas compared to a few years ago, answering Yes (score 1) or No/I don't know (score 0). Total score range: 0-8. Developed by Galvin JE et al. at Washington University in St. Louis, the AD8 achieves approximately 85% sensitivity and 86% specificity for clinical dementia (CDR 0.5 or above) at a cutoff of 2 or above.

An AD8 score of 2 or above is a positive screen, indicating the informant has observed significant cognitive and/or functional changes that warrant formal evaluation. A positive AD8 does not diagnose dementia — it indicates a need for comprehensive cognitive assessment. AD8 of 2-3 with a reliable informant warrants formal evaluation within 1-3 months. AD8 of 4 or above, especially in combination with caregiver concern or clinical observation, warrants urgent evaluation within 2-4 weeks.

The AD8 asks informants whether they have noticed a change in: (1) Judgment (e.g., problems with decisions, being tricked or scammed). (2) Interests in hobbies/activities. (3) Repeating/asking the same thing over and over. (4) Learning to use a tool, appliance, or gadget. (5) Remembering the correct month or year. (6) Handling complicated financial matters. (7) Remembering appointments or medications. (8) Thinking and/or memory problems.

AD8 administration takes 3-5 minutes when administered by a clinician or nurse in a structured interview format. As a waiting-room self-completion questionnaire, informants typically take 2-5 minutes to complete. This brevity makes AD8 one of the most practical cognitive screening tools for high-volume primary care and ED settings. The simple Yes/No/I don't know response format requires no training for informants and minimal clinician instruction time.

Yes. AD8 telephone administration has been validated and shows similar diagnostic accuracy to face-to-face administration. Telephone AD8 is particularly useful for: remote informant screening before an in-person evaluation, telephone-based community dementia screening programs, and family informant interview when the informant cannot accompany the patient to clinic. Telephone AD8 sensitivity was approximately 83% and specificity approximately 89% in Washington University validation studies.

AD8 and MMSE are complementary rather than competing tools. MMSE: direct cognitive performance test, patient-administered, sensitive to education and language effects, provides specific cognitive domain information. AD8: informant-based, captures real-world functional change, education- and language-independent, captures anosognosic patients who perform well on testing. Key comparison: MMSE sensitivity for early dementia is approximately 79-80%; AD8 informant sensitivity is approximately 85%. Combined AD8 plus MMSE sensitivity exceeds 90% for clinical dementia. Use AD8 when an informant is available to complement (not replace) direct cognitive testing.

Online Medical Tools — AD8 Screen

AD8 Screen

How It Works

Select an informant and administer the 8-item AD8 interview

Calculate the AD8 total score (0-8)

Interpret AD8 score and integrate with clinical assessment

Who Uses the AD8 Screen

Primary Care and Annual Wellness Visit Cognitive Screening

Memory Clinic Pre-Screening and Triage

Emergency Department Cognitive Screening

Nursing Home Admission Cognitive Baseline

Alzheimer's Disease and Dementia Research Screening

Community Dementia Case Finding Programs

Pro Tips

Administer AD8 before the clinic visit — waiting room completion is a practical approach

The AD8 captures recent change — it is not anchored to a fixed time point

AD8 of 2 or above is a screening threshold — not a diagnosis

AD8 self-completion by patients shows systematically lower scores than informant version

Combine AD8 with brief direct cognitive testing for optimal sensitivity-specificity balance

High AD8 scores (6-8) suggest urgent evaluation — don't defer

Common Questions About Your Results

Evidence-Based Methodology

Clinical Content Trust

How to Interpret Your Result

When to Use This Tool

Limitations

Sources

Changelog

Related Tools

IQCODE-16

CDR Global

SLUMS Score

MoCA Score

Further Reading

A Comprehensive Guide to Geriatric Medicine: Assessment Tools and Aging Health

Frequently Asked Questions