Comparative validity of informant tools for assessing pre‐stroke cognitive impairment

Abstract

Objectives Various informant‐based questionnaires are used in clinical practice to screen for pre‐stroke cognitive problems. However, there is no guidance on which tool should be preferred. We compared the validity of the two most commonly used informant‐based tools. Methods We recruited consecutively admitted stroke patients. Patients' informants completed the Informant Questionnaire for Cognitive Decline in the Elderly Short Form (IQCODE‐SF, 16‐item) and Ascertain Dementia 8 (AD8). We assessed construct validity (accuracy) against a semi‐structured clinical interview for dementia or mild cognitive impairment (MCI), describing test accuracy metrics and comparing area under ROC curves (AUROC). We described criterion validity by evaluating associations between test scores and neuroimaging markers of dementia and overall ‘brain frailty’. Finally, we described prognostic validity comparing ROC curves for 18‐month clinical outcomes of dementia, death, stroke, and disability. Results One‐hundred‐thirty‐seven patient‐informant dyads were recruited. At usual clinical cut‐points, the IQCODE‐SF had comparable sensitivity to the AD8 (both = 92%) for pre‐stroke dementia, but superior specificity (IQCODE‐SF: 82% vs. AD8: 58%). Youden index suggested that the optimal AD8 threshold for diagnosis of dementia is ≥4. The IQCODE‐SF demonstrated stronger associations with markers of generalised and medial‐temporal lobe atrophy, neurovascular disease, and overall brain frailty. IQCODE‐SF also demonstrated greater accuracy for predicting future dementia (IQCODE‐SF AUROC = 0.903, 95% CI = 0.798–1.00; AD8 AUROC = 0.821, 95% CI = 0.664–0.977). Conclusions Both IQCODE‐SF and AD8 are valid measures of pre‐stroke dementia. Higher cut points for AD8 may improve performance in the acute stroke setting. Based on consistent superiority across a range of validity analyses, IQCODE‐SF may be preferable to AD8 for pre‐stroke dementia screening.

Validity, feasibility, and effectiveness of a voice‐recognition based digital cognitive screener for dementia and mild cognitive impairment in community‐dwelling older Chinese adults: A large‐scale implementation study

“…However, evidence suggests that informants of the participants are often difficult to reach in primary healthcare settings or in the community due to lack of awareness or scheduling conflicts which are universal issues for informant-based cognitive screening. 33,34 This is consistent with our findings, which showed a low completion rate of only 10.1% for the informant AD8. As a potential solution to overcome these barriers, digital cognitive tests have been developed and studied in recent years.…”

“…Other screening tools, such as the AD8 and IQCODE, rely on informant cooperation. However, evidence suggests that informants of the participants are often difficult to reach in primary healthcare settings or in the community due to lack of awareness or scheduling conflicts which are universal issues for informant‐based cognitive screening 33,34 . This is consistent with our findings, which showed a low completion rate of only 10.1% for the informant AD8.…”

Diagnostic accuracy of Ascertain Dementia 8-item Questionnaire by participant and informant–A systematic review and meta-analysis

“…In the tertiary care/hospitalized setting, three studies with 289 patients were included, of which two were prospective cohort studies [ 47 , 48 ], and one was cross-sectional [ 46 ]. The mean age was 72.0 ± 16.1 years old, and 50.9% were female.…”

“…The iAD8 was used in 11 studies (2,021 participants) at a cut-off of two to detect CI (MCI or dementia) [ 7 , 10 , 14 , 32 , 34 , 36 , 37 , 39 , 42 , 46 , 48 ]. The overall prevalence of CI determined by the reference standard was 66% (95% CI: 64, 68%).…”

Using home monitoring technology to study the effects of traumatic brain injury on older multimorbid adults: protocol for a feasibility study

“…Information on medical history and medication will be obtained. The Informant Questionnaire on Cognitive Decline in the Elderly,30 31 which has been used in previous studies to screen for pre-stroke cognitive impairment,32 will be used to screen for pre-TBI cognitive impairment for patients without a formal dementia diagnosis.…”