(1) Background: Postoperative delirium (POD) is an undesirable event especially for older patients after surgery. Perioperative risks for POD development are multiple, but gender differences are still poorly considered. In this observational study, predisposing and precipitating risk factors of POD and the possible gender influence are distinguished. (2) Methods: This observational prospective trial enrolled 1097 patients in a tertiary hospital from September 2018 until October 2019. POD was considered positive, if one of the tests Confusion Assessment Method for ICU (CAM-ICU) or Confusion Assessment Method (CAM), 4 'A's Test (4AT) or Delirium Observation Screening (DOS) scale was positive on one of five assessment days. (3) Results: POD incidence was 23.5% and the mean age of study population was 72.3 ± 7.3 years. The multiple logistic regression model showed a significant impact of age (Odds Ratio (OR) 1.74; 95% Confidence Interval (CI): 1.37-2.22), American Society of Anesthesiologists (ASA) (OR 1.67; 95% CI: 1.25-2.26), surgery risk (OR 2.10; 95% CI: 1.52-2.95) and surgery duration (OR 1.17; 95% CI: 1.07-1.28), ventilation time (OR 1.64; 95% CI: 1.27-2.24), as well as the male sex (OR 1.74; 95% CI: 1.37-2.22) on POD risk. (4) Conclusions: Perioperative and predisposing risk factors had an impact on the development of POD. The influence of male sex should be considered in future research.
Keywords: gender difference; older adults; postoperative delirium; risk factors.