Performance of three clock scoring systems across different ranges of dementia severity.

The ability of three different Clock Drawing Test (CDT) scoring systems to detect Dementia of the Alzheimer Type (DAT) was investigated. As part of a neuropsychological battery, fifty DAT Type patients and fifty matched controls drew a clock. Each drawing was scored by three independent raters according to three different scoring systems: the 3-Factor system, the Template system, and the Abbreviated system.