Comparison of two screening instruments to detect dementia in Indian elderly subjects in a clinical setting

Cognitive screening in elderly patients receiving treatment for chronic medical conditions in a busy outpatient clinical setting is crucial to detect dementia at an earlier stage. Although Hindi Mini-Mental State Examination (HMSE) is an established screening tool for the geriatric population in India, but cannot be administered with the informant. Our study aims to compare two screening instruments, Informant based - Eight-item Interview to Differentiate Aging and Dementia (AD8) and HMSE among elderly patients attending medical outpatient service (OPD) in a tertiary care hospital.

A total of 776 subjects aged ≥65 years and receiving treatment from medicine OPD in a tertiary care hospital were screened for dementia using AD8 and HMSE. The clinical diagnosis was established after detailed clinical assessment using ICD-10 criterion. Sensitivity and specificity were calculated for both screening tools and ROC curves were plotted considering ICD-10 diagnosis as the gold standard.

Comparison of receiver operating characteristic (ROC) curves showed that HMSE (AUC = 0.77) were better than AD8 (AUC = 0.61) in detecting dementia. Although increasing the cut-off value of AD8 from a recommended score of ≥2 to ≥3 improved sensitivity from 35% to 48.9%, high false-positive rate limited its utility as a cognitive screening tool.

Although AD8 is easy to use and quickly administered with either patient or informant, it does not seem to be a suitable cognitive screening test for Indian elderly with chronic medical disorders. HMSE at a cut-off score of ≤23 is able to find out dementia among geriatric patients in a busy medical setting.