Interrater reliability of three clock drawing test scoring systems

This study demonstrates the reliability of 3 Clock Drawing Test (CDT) scoring systems when applied to the protocols of stroke patients. The sample included 20 randomly selected sets of both freehand and predrawn circle versions ofthe CDT completed by patients undergoing comprehensive stroke rehabilitation. The protocols were scored independently by 2 raters using each of 3 published scoring systems (Freedman et al., 1994; Libon, Malamut, Swenson, Sands, & Cloud, 1996; Rouleau, Salmon, Butters, Kennedy, & McGuire, 1992). Interrater agreement and intrarater consistency were measured using the intraclass correlation coefficient (ICC). The results demonstrate that the raters used comparable criteria for each score (high interrater reliability) and that each applied similar scoring criteria throughout the set of protocols (high intrarater consistency). Scores related to the overall contour of the clockface tended to have lower ICCs. Reliability coefficients were comparable for both CDT versions. The results provide evidence for the accurate and consistent scoring of the CDT in stroke.