Screening for Alzheimer's disease among illiterate elderly: accuracy analysis for multiple instruments

Area of Science:

• Neurology
• Geriatrics
• Psychometrics

Background:

• Dementia screening in developing countries faces challenges due to educational and cultural performance variations.
• Accurate discrimination between Alzheimer's disease (AD) and normal aging in illiterate elderly populations is crucial for timely intervention.

Purpose of the Study:

• To evaluate the diagnostic accuracy of individual and combined screening tests for Alzheimer's disease (AD) in illiterate elderly patients.
• To identify the most effective screening instruments and protocols for discriminating AD from normal cognition in an illiterate clinical sample.

Main Methods:

• A cross-sectional study involving 66 illiterate outpatients with mild/moderate AD and 40 illiterate controls.
• Utilized Mini-Mental State Examination (MMSE), Verbal Fluency (VF), Clock Drawing Test (CDT), and Pfeffer Functional Activities Questionnaire (PFAQ).
• Analyzed test performance using Receiver Operating Characteristic (ROC) curves for sensitivity and specificity, including pairwise combinations.

Main Results:

• All cognitive (MMSE, CDT, VF) and functional (PFAQ) assessments showed significant differences between AD patients and controls (p < 0.001).
• The Mini-Mental State Examination (MMSE) and Pfeffer Functional Activities Questionnaire (PFAQ) were the best individual screening instruments.
• Combined MMSE and PFAQ achieved 94.1% sensitivity, while MMSE and CDT yielded 89% specificity.

Conclusions:

• Illiterate elderly individuals with Alzheimer's disease can be effectively screened using established cognitive and functional assessment tools.
• Combined screening protocols, particularly involving the MMSE and PFAQ or MMSE and CDT, enhance diagnostic accuracy for AD in illiterate populations.