Primary care screen for early dementia

Abstract

Objectives: To determine whether the Alzheimer's Disease Screen for Primary Care (ADS-PC) is more sensitive to early dementia than the Mini-Mental State Examination (MMSE) and whether it has as high a misclassification rate in minority patients and patients with limited education.

Design: Cross-sectional validation study.

Setting: Urban geriatric primary care practice.

Participants: Three hundred sixteen African-American and Caucasian patients, including 55 patients with early dementia (Clinical Demential Rating of 0.5).

Measurements: The ADS-PC is a two-stage strategy for identifying early dementia that consists of a brief high-sensitivity dementia screen, applied to all patients aged 65 and older, and a second stage to identify memory impairment, applied to patients who fail the first stage. Differences in the sensitivities or specificities of the ADS-PC and the MMSE were evaluated using the McNemar test.

Results: Receiver operating characteristic curves were used to examine differences in the operating characteristics of the ADS-PC across a range of cutscores. When the specificities of both tests were equated (0.90), the sensitivities were significantly different (ADS-PC, 0.75; MMSE, 0.56). The MMSE failed to identify five times as many cases of dementia as the ADS-PC. When the sensitivities were equated, the specificities differed significantly (ADS-PC, 0.95; MMSE, 0.73). The MMSE misclassified five times as many noncases as the ADS-PC. This pattern of significantly higher sensitivity and specificity for the ADS-PC than for the MMSE was repeated in the results according to race and for individuals with high school or more education but not in individuals with less education.

Conclusion: The ADS-PC outperformed the MMSE in identifying early dementia in a racially and educationally diverse primary care cohort.