Abstract: Objective To investigate the predictive factors of death within 2 years  after lower extremity fracture surgery in elderly patients. 
Methods Clinical data were collected from patients aged ≥65 years who underwent elective lower extremity fracture surgery. According to the survival status after operation within 2 years, patients were assigned into survival group and death group. Multivariate Cox regression analysis was performed on the factors with statistically difference between the two groups and predictive factors of death within 2 years were screened out. Receiver operation characteristic(ROC) curves and calculation of area under the ROC curve(AUC) were used to assess the predictive ability of the above factors.  
Results The data of 372 patients were eventually included for statistical analysis. Among them, 55 deaths occurred within 2 years and the overall mortality was 14.7%. Cox regression analysis revealed that age ≥75 years(HR:2.155, 95%CI:1.093-4.247), American Society of Anesthesiologists(ASA) grade ≥3(HR:2.978, 95%CI:1.242-7.183), Charlson Comorbidity Index(CCI) score≥2(HR:4.649, 95%CI:2.467-8.761), preoperative anemia(HR:2.050, 95%CI:1.066-3.943), cardiocerebral vascular events during postoperative hospital stay(HR:3.026, 95%CI:1.491-6.140) were the predictive factors of death within two years after operation. The AUC was 0.677, 0.733, 0.700, 0.584 and 0.658, respectively. The AUC of the combination of the above five predictive factors was 0.858, which was significantly higher than the AUC of each factor alone. ASA grade  ≥3 was the most sensitive with a sensitivity of 87.3% and CCI≥2 was the most specific with a specificity of 92.7%. 
Conclusion Age≥75 years, ASA grade ≥3, CCI score ≥2, preoperative anemia and postoperative cardiocerebral vascular events can be predictive factors of death within 2 years after following lower extremity fracture surgery in elderly patients. The combined use of these five predictive factors was superior for death prediction than each factor alone. It is suggested that targeted perioperative intervention may help improve long-term quality of life of elderly patients.

Key words: fractures, elderly patients, postoperative death