Screening for dementia by telephone using the Memory Impairment Screen

OBJECTIVES: To develop and assess telephone-based screening tests for dementia, especially Alzheimer's disease (AD). DESIGN: A cross-sectional validation study nested within a longitudinal study of aging and dementia. SETTING: The Einstein Aging Study of the Albert Einstein College of Medicine, Bronx, New York. PARTICIPANTS: Three hundred elderly community volunteers living in Bronx County, 27 of whom were diagnosed with dementia based on in-person clinical evaluation. Of the 27 individuals with dementia, 18 had AD. MEASUREMENTS: A telephone battery was administered that included the Memory Impairment Screen by telephone (MIS-T, a test of semantic memory), the Category Fluency Test (CF-T), and the Telephone Instrument for Cognitive Status (TICS). An in-person evaluation then followed that included a neurological examination, a neuropsychological battery, demographics, and medical history. RESULTS: The telephone battery was well accepted. The MIS-T required 4 minutes; the CF-T, 3 minutes; and the TICS, 10 minutes. The MIS-T had excellent sensitivity and specificity when compared with the CF-T and the TICS. Using cutscores on all three tests that provide a sensitivity of 78%, specificity was significantly higher for the MIS-T (93%) than for the CF-T (78%, P <.05) or the TICS (80%, P<.05). Combining the MIS-T and CF-T improved discriminative validity but increased screening time and the complexity of scoring. Normative data for the MIS-T, the CF-T, and the TICS for use in settings with different base rates (prevalence) of dementia are presented in this study. CONCLUSION: The MIS-T outperforms the CF-T and the TICS as a valid and time-efficient telephone screen for dementia. For applications that require optimal efficiency and accuracy, the MIS-T is recommended.