Risk factors for 1-year death after surgery in elderly patients with hip fractures and accuracy of prediction model: based on LASSO-logistic regression / 中华麻醉学杂志

ABSTRACT

Objective:To identify the risk factors for 1-year death after surgery in elderly patients with hip fractures and evaluate the accuracy of the prediction model based on LASSO-logistic regression analysis.Methods:A case-control study was conducted on elderly patients (age ≥65 yr) who underwent surgical treatment for hip fractures in the Second Affiliated Hospital of Wenzhou Medical University from January to December 2019. Patients were divided into death group and survival group according to their survival status at 1-year after surgery. General data and preoperative laboratory indicators were obtained. The variables were selected by utilizing LASSO regression and incorporated into multivariate logistic regression analysis to identify the risk factors for 1-year death after surgery in elderly patients with hip fractures. Then a prediction model was established based on the results and evaluated.Results:There were 63 patients in death group and 564 in survival group. The results of LASSO regression and multivariate logistic regression analysis showed that age, preoperative cognitive dysfunction, Chalson comorbidity index ≥3 points and preoperative serum prealbumin level were the independent risk factors for 1-year death after surgery in elderly patients with hip fractures ( P<0.05). The area under the receiver operating characteristic curve of the prediction model was 0.788 (95% confidence interval [0.731-0.846]), with the sensitivity and specificity of 76.2% and 68.6% respectively. The average absolute error of the calibration curve was 0.007. The results of Hosmer-Lemeshow goodness-of-fit test showed that there was no significant difference between the predicted value and actual observed value ( χ2=5.065, P=0.751). Decision curve analysis showed that patients had a high net benefit rate when the threshold probability range was 0-0.7. Conclusions:Age, preoperative cognitive dysfunction, Chalson comorbidity index ≥3 points and preoperative serum prealbumin level are the independent risk factors for 1-year death after surgery in elderly patients with hip fractures, and the prediction model developed based on LASSO-logistic regression has high accuracy.