The AD8 is an 8-item informant-based screen for early dementia developed at Washington University in St. Louis (Galvin et al. 2005). Unlike performance tests such as the MMSE or SLUMS, it asks someone who knows the patient well whether there has been *change* over recent years in memory, orientation, judgement and daily function - each item answered yes/no, total 0-8. Because it measures intra-individual change rather than a snapshot of ability, it is less confounded by education, language and baseline ability, and it can be completed when the patient cannot be tested directly.
02 - Origin & purpose
Where it comes from.
The AD8 was developed at Washington University in St. Louis and first described by Galvin and colleagues in 2005 (Neurology). It was designed to address a gap that performance tests leave open: detecting early dementia when a knowledgeable informant can describe decline that a single bedside assessment might miss. The instrument is copyright Washington University in St. Louis.
03 - Scoring & cutoffs
How scoring works.
A score of 0-1 is considered normal cognition; 2 or more endorsed items suggests cognitive impairment and warrants further assessment. In the original validation (Galvin 2005), the >=2 cutoff gave an area under the curve of 0.834, sensitivity 74% and specificity 86% for very mild dementia (CDR-based), with sensitivity rising to 85% when milder-to-severe dementia cases were included. The 2019 Cochrane review (Hendry et al.) pooled seven studies at the >=2 cutoff: sensitivity 0.92 (95% CI 0.86-0.96) but specificity 0.64 (0.39-0.82); at >=3, sensitivity 0.91 and specificity 0.76. The pattern - high sensitivity, modest specificity - fits a screen: a positive AD8 identifies people who need proper assessment, it does not diagnose dementia.
04 - Validation evidence
How well it performs.
The AD8 was validated against Clinical Dementia Rating (CDR) staging in the original 2005 cohort, reporting an AUC of 0.834 for very mild dementia at the >=2 cutoff. The 2019 Cochrane review pooled seven studies and confirmed a high-sensitivity, modest-specificity profile, consistent with a screening tool rather than a diagnostic one.
0.834
AUC
>=2 cutoff, very mild dementia (CDR-based), Galvin 2005
0.92
Sensitivity (>=2)
95% CI 0.86-0.96, Cochrane pooled (7 studies)
0.64
Specificity (>=2)
95% CI 0.39-0.82, Cochrane pooled
0.91
Sensitivity (>=3)
Specificity 0.76, Cochrane pooled
05 - How it compares
How it compares to the alternatives.
Instrument
Items
Time
When to reach for it
AD8
8
~3 min
Informant interview. Detects decline when a knowledgeable informant is available. Licensed (Washington University).
General-practice screen with patient and informant sections. Free for clinical use.
IQCODE
16
~5 min
The other established informant questionnaire (16-item short form). Useful when a longer informant view is wanted.
06 - When to use it
Right tool, wrong tool.
The AD8 is best used when an informant is available and the patient cannot be tested directly, or when there is concern about decline despite normal performance-test scores in highly educated patients. It is also useful in primary-care triage before referral.
Reach for it when
-An informant who knows the patient well is available
-The patient cannot be tested directly (severe illness, sensory impairment, language barrier)
-Concern about decline despite normal performance-test scores in highly educated patients
-Primary-care triage before referral
Reach for something else when
-No reliable informant is available
-As a stand-alone diagnostic - it is a screen, not a diagnosis
-Monitoring change over short intervals
07 - Confidence & precision
Reading the score with care.
The AD8's strength is sensitivity: the Cochrane pooled estimate of 0.92 at the >=2 cutoff means it catches most cases, but the modest specificity (0.64) means false positives are common. A positive screen must always be followed by full assessment. The informant's familiarity with the patient and the timeframe of observation influence accuracy - an informant who sees the patient daily over years gives a more reliable picture than a distant contact.
08 - Limitations
What it cannot tell you.
The AD8 cannot diagnose dementia - it flags the need for assessment. It depends entirely on having a reliable informant, and the informant's judgment of change is subjective. It is less suited to monitoring change over short intervals because it asks about decline over an indefinite recent period, not a fixed window. A patient self-report version exists but performs less well than the informant version.
09 - Licensing, explained
How licensing works.
The AD8 is copyright Washington University in St. Louis. Reproduction is permitted without modification solely for clinical care (a clinician's own non-research patient care) and non-commercial, investigator-initiated research. Clinical-trial and commercial uses - including electronic publication - require Washington University's prior written permission.
Because of this, Aisel cannot host the instrument, offer a scorable version, or reproduce the 8 items on this page. This page is an information resource: it explains scoring, cutoffs and evidence, but contains no AD8 item text. Clinicians can obtain the form for their own practice via Washington University or the Alzheimer's Association.
See how Aisel removes friction where it costs most. A 20-minute walkthrough tailored to your clinic.
We value your privacy
We use cookies to analyse site usage and improve your experience. Analytics and embedded media (e.g. YouTube) only load if you accept. Read our cookie policy.