Hemoglobin to red cell distribution width ratio predicts postoperative delirium in older patients undergoing hip fracture surgery: A retrospective cohort study

Aim: This study aimed to investigate the predictive effect of hemoglobin to red cell distribution width ratio (HRR) on postoperative delirium (POD) in older patients undergoing hip fracture surgery. Methods: POD was diagnosed by capturing descriptive words from the medical records. The correlation between POD and HRR was determined using logistic regression analysis, and the receiver operating characteristic curve was used to further evaluate the value of HRR in predicting POD. Results: In total, 202 older patients accepting hip fracture surgery were included in our study. The result of multiple logistic regression analysis presented HRR (odds ratio, 0.504 [95% confidence interval, 0.340-0.747]; P < 0.001), American Society of Anesthesiologists physical status >2, and neutrophils were independently correlated with POD. The area under the curve of HRR was 0.746 (95% confidence interval, 0.676-0.815), and the optimal cutoff value was 8.322. Conclusions: HRR, American Society of Anesthesiologists physical status >2 and neutrophils could independently predict POD in older patients undergoing hip fracture surgery, and HRR had satisfactory predictive value. However, further research is needed to confirm our findings.