Neutrophil-to-Lymphocyte Ratio (NLR) Could Serve as a Potential Marker for Delirium and Delirium Duration in Geriatric Patients with Hip Fracture: A Retrospective Study

Abstract Purpose Postoperative delirium (POD) is an independent risk factor not only for mortality but also for institutionalization and dementia. The purpose of this study was to investigate the risk factors, which is related to the pathogenesis of POD, in geriatric patients with hip fracture. Methods 1,242 Eligible patients with hip fracture were enrolled. Receiver operating characteristic (ROC) curve was performed to identify the optimal cut point of NLR for POD. The relationship between NLR and POD occurrence, NLR and POD duration were analyzed by multivariable analysis. Results ROC curve showed that the optimal cut point of NLR for POD was NLR ≥ 7.6. Multivariate logistic regression analysis showed that NLR ≥ 7.6 (odds ratio [OR] 2.75, [95% confidence interval [CI] 1.51 to 5.02], p = 0.001), stroke (OR 1.05, [95% CI 1.02 to 1.09], p = 0.005), complications, general anesthesia, long length of stay were risk factors of POD, with the largest effect for NLR ≥ 7.6. NLR ≥ 7.6 (OR 0.59, [95% CI 0.209 to 0.886], p = 0.038), older age (OR 0.054, [95% CI 0.009 to 0.099], p = 0.019), previous stroke (OR 0.908, [95% CI 0.085 to 1.731], p = 0.031), and previous heart failure (OR 1.679, [95% CI 0.448 to 2.910], p = 0.008) suggested long POD duration. Conclusions NLR could be used as a potential marker for prediction of POD and POD duration in geriatric patients with hip fracture.