A Brief Dementia Test with Subjective and Objective Measures

BACKGROUND The development of an effective brief dementia test will help in the early identification of dementia. AIM This study investigates the diagnostic utility of a brief cognitive test for dementia which combines a short subjective informant-rated questionnaire (AD8) with an objective cognitive measure (Mini-Mental State Examination, MMSE) or its subcomponents. METHODS Subjects with mild dementia (Clinical Dementia Rating Scale score ≤1) were matched with community-dwelling, cognitively intact controls. MMSE and Clinical Dementia Rating Scale were administered to all subjects, while AD8 was completed by a reliable informant. Receiver operating characteristics analysis determined the diagnostic accuracies of AD8, MMSE, and AD8 combined with MMSE (AD8+MMSE). Stepwise logistic regression identified the subcomponents of MMSE which, combined with AD8, best discriminated dementia patients from controls. RESULTS The AD8 (area under the curve [AUC] = 0.92, 95% confidence interval [CI] 0.89-0.95) was superior to the MMSE (AUC = 0.87, 95% CI 0.83-0.92) in discriminating mild dementia patients from controls, and AD8+MMSE (AUC = 0.95, 0.92-0.98) increased its superior discrimination over MMSE alone. AD8 combined with three-item recall and intersecting pentagon copy (AUC = 0.95, 95% CI 0.92-0.97) performed as well as AD8 combined with full MMSE. CONCLUSION AD8 combined with the MMSE subcomponents three-item recall and intersecting pentagon copy has excellent diagnostic utility and is a promising brief cognitive test for early dementia.