Predictive value of the Clock Drawing Test. A review of the literature.

BACKGROUND/AIMS The Clock Drawing Test (CDT) assesses cognition focusing on executive function and praxis in contrast to the more language-based Mini-Mental State Exam. The CDT may allow early identification of cognitive decline. METHODS A systematic review of the literature was used to identify studies that had used the CDT to predict future cognitive impairment. RESULTS Five studies were found with the CDT as a predictor. The data were too disparate for meta-analytic techniques. CONCLUSION The CDT may be a useful tool to identify decline before more traditional screening tests; however, further studies are needed as the data are sparse and heterogeneous.