Abstract
The Clock Drawing Test is a cognitive screening tool gaining popularity in the perioperative setting. We compared 3 common scoring systems: (1) the Montreal Cognitive Assessment; (2) the Mini-Cog; and (3) the Libon scale. Three novice raters acquired interrater and intrarater reliability for each scoring system and then scored 738 preoperative clock drawings with each scoring system. Final scores correlated with each other but with notable discrepancies, indicating the need to attend to interrater and intrarater reliability when implementing any scoring approach in a clinical setting.