Background: Postoperative delirium is a common and important complication in cancer patients. We need to identify patients at high risk of postoperative delirium such that it can be prevented preoperatively or in early postoperative phase. The aim of this study was to investigate whether preoperative anxiety predicted onset of postoperative delirium in cancer patients, not only in order to identify high-risk groups but also to help develop new preventive approaches.
Methods: This was a prospective observational cohort study of cancer patients undergoing tumor resections. Postoperative delirium was assessed using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Preoperative anxiety was evaluated with the Hospital Anxiety and Depression Scale-Anxiety (HADS-A), and we defined HADS-A > 7 as clinical anxiety. We conducted multivariate logistic regression to determine which factors were predictors of delirium.
Results: The final analysis included 91 patients, 29 of whom met the criteria for postoperative delirium. In multivariable logistic regression, age (5-year increments; odds ratio (OR) = 1.565, 95% confidence interval (CI) = 1.057-2.317, p = 0.025) and HADS-A > 7 (OR = 4.370, 95% CI = 1.051-18.178, p = 0.043) predicted delirium onset. These variables explained 74.2% of the variance.
Conclusions: Preoperative anxiety strongly predicted postoperative delirium in cancer patients. Our findings suggest that preoperative anxiety may be a new target for prevention of postoperative delirium. Trial registration number This study was registered at UMIN000018980.