JMIR Publications

ABSTRACT

Background:

Undiagnosed cognitive impairment poses a global challenge, prompting recent interest in ultra-brief screening questionnaires (comprising <2–3 items) to efficiently identify individuals needing further evaluation. However, evidence on ultra-brief questionnaires remains limited, particularly regarding their validity across diverse literacy levels.

Objective:

(1) To develop an ultra-brief questionnaire that performs well in detecting cognitive impairment (i.e. mild cognitive impairment or dementia; MCI/dementia) across diverse literacy; (2) To compare its performance with an established questionnaire (AD8; The Eight-item Informant Interview to Differentiate Aging and Dementia).

Methods:

This diagnostic study involved 1,856 participants aged ≥65 years (median education=10 years; range=0–23 years), prospectively recruited from community settings in Singapore. Participants and informants completed 15 cognition-related questions. MCI/dementia were diagnosed via comprehensive assessment and consensus conference. Sample was randomly split 70/30 – Training sample (70%) was used to derive an ultra-brief questionnaire from the 15 cognition-related questions (using an exhaustive search approach); Test sample (30%) evaluated area under the receiver operating characteristic curve (AUC).

Results:

The new questionnaire comprised two informant questions (Assistance with medications and Worry about cognition), plus Age and Years of education. It demonstrated excellent performance in detecting MCI/dementia (AUC=85%, 95%CI=80–90%), significantly better (p=0.003) than a nested baseline model (comprising Age and Years of education; AUC=78%, 95%CI=73–83%). In contrast, AD8 had an AUC of 76% (95%CI=70–83%), not significantly different (p=1.000) from the baseline model. The questionnaire’s performance was consistent across education subgroups and varying prevalence scenarios. Two optimal cutoffs were used – the lower cutoff provided 80% sensitivity and 96% negative predictive value; the upper cutoff provided 99% specificity and 81% positive predictive value. A web-based calculator is available for public use.

Conclusions:

This ultra-brief questionnaire enables rapid screening for cognitive impairment (in <1 minute) by family members or as part of community geriatric assessments. Its excellent performance across literacy levels supports its utility for case-finding in diverse populations, including underserved communities and lower- and middle-income countries.