| Utility of self-rated vs informant-rate AD8 (Ascertain Dementia 8) for detection of early cognitive impairment: Experience of a “real-world” memory clinic |
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Khin Khin Win1,2, Justin Chew1,2, . Jun Pei Lim1,2, Esther Ho1,2, Noorhazlina Ali1,2, Mark Chan1,2, Wee Shiong Lim1,2 |
1Department of Geriatric Medicine, Tan Tock Seng Hospital (TTSH), Singapore
2Institute of Geriatrics and Active Ageing, Tan Tock Seng Hospital (TTSH), Singapore
3Lee Kong Chian School of Medicine, Nanyang Technological University |
Correspondence:
Khin Khin Win,
Email: khin_win_KHIN@ttsh.com.sg
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Received: 29 May 2025 • Revised: 7 November 2025 • Accepted: 26 November 2025 |
| Abstract |
Background
The AD8 is a validated informant-based interview for early dementia detection. Research suggests the utility of self-rated AD8 to identify milder dementia forms in research settings. This study compares the factor structure, reliability, and diagnostic performance between AD8-self and AD8-informant for early cognitive impairment (ECI) in a clinical setting.
Methods
515 patient-informant dyads [43 cognitively intact and 472 ECI] from a tertiary memory clinic completed both self-reported and informant AD8. We conducted exploratory factor analysis to determine the factor structure, Cronbach’s alpha for internal consistency, and receiver operating characteristic (ROC) curve analysis for ECI, including a subgroup analysis for mild cognitive impairment (MCI).
Results
The mean age and education of ECI participants were 75.61 years (range, 51-95) and 5.6 years (range, 0-20), respectively, and 72.6 years (range, 51-89) and 6.8 years (range, 0-16) in the MCI subgroup. Unlike AD8-informant’s one-factor structure, AD8-self had a two-factor structure corresponding to memory and non-memory domains. AD8-self demonstrated lower reliability (Cronbach’s Alpha: ECI 0.666 vs. 0.764; MCI 0.663 vs. 0.709). In ECI, AD8-informant (cut-off ≥3) showed better diagnostic performance (Sensitivity: 89%, Specificity: 79%) than AD8-self (cut-off ≥4) (Sensitivity: 27.1%, Specificity: 95.3%) (AUC: 0.915 vs. 0.593, p<0.001). Similar results were found in MCI (Sensitivity: 64.7% vs 26.5%; Specificity:79.1% vs 95.3%; AUC:0.745 vs 0.600, p=0.002).
Conclusion
AD8-self has a distinct factor structure, lower reliability, and inferior diagnostic performance compared to AD8-informant for ECI/MCI detection. Our result do not support AD8-self as a standalone tool for detecting ECI or MCI. |
| Key Words:
Mental state and dementia tests, Mild Cognitive Impairment, Reproducibility of results |
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