A novel digital clock drawing test as a screening tool for perioperative neurocognitive disorders: A feasibility study

Acta Anaesthesiol Scand. 2020 Dec 9. doi: 10.1111/aas.13756. Online ahead of print.

Abstract

Background: We developed a digital clock drawing test (dCDT), an adaptation of the original pen and paper clock test, that may be advantageous over previous dCDTs in the perioperative environment. We trialed our dCDT on a tablet device in the preoperative period to determine the feasibility of administration in this setting. To assess the clinical utility of this test, we examined the relationship between the performance on the test and compared derived digital clock measures with the 4 A's Test (4AT), a delirium and cognition screening tool.

Methods: We recruited a sample of 102 adults aged 65 years and over presenting for elective surgery in a single tertiary hospital. Participants completed the 4AT, followed by both command and copy clock conditions of the dCDT. We recorded time-based clock-drawing metrics, alongside clock replications scored using the Montreal Cognitive Assessment (MoCA) clock scoring criteria.

Results: The dCDT had an acceptance rate of 99%. After controlling for demographic variables and prior tablet use, regression analyses showed higher 4AT scores were associated with greater dCDT time (seconds) for both command (β = 8.2, P = .020) and copy clocks (β = 12, P = .005) and lower MoCA-based clock scores in both command (OR = 0.19, P = .001) and copy conditions (OR = 0.14, P = .012).

Conclusion: The digital clock drawing test is feasible to administer and is highly acceptable to older adults in a preoperative setting. We demonstrated a significant association between both the dCDT time and clock score metrics, with the established 4AT. Our results provide convergent validity of the dCDT in the preoperative setting.

Keywords: aging; cognition; cognitive screening; feasibility; perioperative neurocognitive disorder.