Background: Currently applied cognitive tests for assessing the risk of post-operative delirium require time and specialised medical staff, in addition to the patients' mental strain. We investigated the four-point scoring Clock-Drawing Test (CDT-4) as a preoperative independent predictor for post-operative delirium.
Methods: A total of 100 consecutive patients aged over 65 years admitted for accidental hip fracture were assessed for delirium using the Confusion Assessment Method Scale. The cognitive function was rated with mini-mental state examination, Montreal Cognitive Assessment Scale (MoCA), and CDT-4. Descriptive statistics were performed, and a logistic regression model for post-operative delirium was applied.
Results: Out of the 100 enrolled patients 98 underwent hip repair surgery and 65 (66%) had post-operative delirium, with 24 (42%) incident cases. The median (IQR) ages were 78 (72-83) and 84 (80-87) years for the non-delirium and post-operative delirium groups, respectively. The logistic regression concluded with age and CDT-4 as independent preoperative predictors, while controlling for gender, pre-surgery delirium, MoCA visual, and MoCA attention: OR 1.32 [95% CI (1.099-1.585); p = 0.003] for age; OR 0.153 [95% CI (0.033-0.719); p = 0.017] for CDT-4.
Conclusions: Employing CDT-4 as a bedside assessment of delirium risk may help to preoperatively stratify and prioritise the patients for preventive perioperative care in a timely manner.