Validation of the 7-minute screen for the detection of early-stage Alzheimer's disease

Background/Aims: The 7-Minute Screen (7MS) is a screening battery to identify individuals with a high probability of Alzheimer's disease (AD). The 7MS consists of four subtests (Temporal Orientation, Enhanced Cued Recall, Clock Drawing, and Verbal Fluency), each measuring a different aspect of cognition. The present study is designed to examine the predictive validity of the 7MS to distinguish between patients with early-stage AD and healthy control subjects. Methods: Sixty-three patients who were diagnosed as having probable or possible AD and 91 community-dwelling elderly individuals of comparable age, sex distribution, and education were administered the 7MS (paper-and-pencil version) and other screening batteries. All patients were rated Clinical Dementia Rating (CDR) 0.5-1, categorized as early-stage AD, and all participants obtained a score of less than 6 for the Geriatric Depression Scale (15-item version). Results: Mean scores for patients and controls on all the four subtests were significantly different. When using the total score of the 7MS, which was calculated by the original logistic regression formula based on all of the four subtests, the sensitivity for early-stage AD was 90.5% with a specificity of 92.3%. Correlation analysis indicated high concurrent validity between the 7MS and existing standard cognitive screening batteries (e.g., MMSE, HDS-R). In correlation analysis and multiple regression analysis, demographic effects (age, sex, and education) were not significantly associated with the total score of the 7MS in controls. Conclusions: The results showed that the 7MS had a high level of sensitivity and specificity. We also found that the 7MS was not affected by demographic characteristics. These findings demonstrated that the 7MS is a useful screening tool for discriminating patients with early-stage AD from intact individuals.