Abstract:

Objective To investigate the role of nomogram models based on C-reactive protein-to-albumin ratio （CAR） and neutrophil-to-lymphocyte ratio（NLR）in predicting 1-year mortality in elderly patients with hip fractures after surgery. Methods A total of 161 elderly patients with hip fractures who underwent hip replacement surgery at Guangxi Zhuang Autonomous Region People's Hospital from January 2019 to December 2021 were enrolled. The clinical data，surgical-related data and preoperative and postoperative laboratory determination results were collected. Cox regression analysis was used to evaluate the independent risk factors for 1-year mortality in elderly patients with hip fractures after surgery. Cox mortality risk models and nomogram models for predicting 1-year mortality and postoperative 3-month，6-month and 1-year survival rates in elderly patients with hip fractures after surgery were established. Receiver operating characteristic（ROC）curve was used to determine the optimal cut-off value for the total score of the nomogram models to distinguish low-risk，medium-risk and high-risk groups. Kaplan-Meier survival curves were used to analyze the 1-year survival of low-risk，medium-risk and high-risk groups after surgery. Results Age，Charlson comorbidity index（CCI），American Society of Anesthesiologists（ASA）classification，postoperative CAR and postoperative NLR were all independent risk factors for 1-year mortality in elderly patients with hip fractures after surgery [hazard ratios（HR）were 2.745，2.486，3.568，2.597 and 2.518，95% confidence intervals（CI）were 1.377-5.993，1.274-3.738，1.148-6.993，1.126-3.957 and 1.343-3.889，respectively，P<0.01]. Cox mortality risk models and nomogram models for predicting 1-year mortality and 3-month，6-month and 1-year survival in elderly patients with hip fractures after surgery were established based on age，CCI，ASA classification，postoperative CAR and postoperative NLR. Postoperative CAR and postoperative NLR in elderly patients with hip fractures were positively correlated with Cox mortality risk scores. It is negatively correlated with postoperative survival time. The area under curve（AUC）for predicting the mortality of elderly hip fracture patients within 1-year after surgery by the combined determination of the 5 factors was 0.940. The 1-year overall survival rates of low-risk，medium-risk and high-risk groups were decreased successively（P<0.05）. Conclusions The nomogram models based on CAR and NLR for predicting the mortality of elderly hip fracture patients within 1-year after surgery has high clinical application value.

Key words: C-reactive protein-to-albumin ratio, Neutrophil-to-lymphocyte ratio, Nomogram model, Hip fracture, Elder, Hip replacement, Death