Optimizing Clock Drawing Scoring Criteria: Development of the West Haven-Yale Clock Drawing Test.

ABSTRACT

BACKGROUND/OBJECTIVES: The Clock Drawing Test (CDT) is a widely used measure, which has been included as a recommended cognitive screen for driving evaluations. This study aimed to develop an optimized scoring method-the West Haven-Yale CDT (WHY-CDT)-based on the scoring methods of Freund and Royall's CLOX, the latter of which is significantly associated with executive control functions. DESIGN: Retrospective cohort study. SETTING: Greater New Haven, Connecticut, area. PARTICIPANTS: A total of 237 adults, aged 70 years and older, who had a current driver's license and drove at least once a month. MEASUREMENTS Clock drawings were independently scored using both scoring systems, as well as a qualitative-based 5-point gestalt score. Interrater reliability was calculated using Light's κ for dichotomous variables and intraclass correlations for continuous variables. A categorical principal component analysis was conducted to determine which items from the Freund and Royall scoring systems should be retained in the modified system, with the Kuder-Richardson test used to assess internal consistency (reliability). RESULTS: The majority of the quantitative scoring items had moderate to almost perfect interrater reliability, with excellent interrater reliability for the qualitative gestalt score. The final scoring method retained seven items from the Freund and Royall versions, of which over 85% were from the latter. Internal consistency was fair to acceptable for the WHY-CDT's two dichotomously scored subscales, but poor for both the Freund and Royall scoring methods. CONCLUSIONS: The WHY-CDT is a simple scoring method that combines elements of the Freund and Royall methods, as well as an overall gestalt score, and has strong interrater reliability. Future directions for use of this modified system are discussed. J Am Geriatr Soc 672129-2133, 2019.