A nomogram model for predicting preoperative DVT in elderly anemic patients undergoing total hip arthroplasty: a retrospective cohort study.

Objectives: Total hip arthroplasty (THA) is classified as a high-risk surgery for venous thromboembolism (VTE) events, especially in elderly individuals and in cases of anemia. This study aims to uncover independent risk factors for predicting preoperative DVT in elderly anemic patients undergoing THA. Furthermore, it seeks to validate these factors' predictive efficacy in diagnosing DVT, with the goal of facilitating prompt identification and treatment to mitigate associated risks.

Methods: Clinical information and relevant laboratory test data of preoperative deep vein thrombosis (DVT) in 459 elderly patients with anemia who underwent total hip replacement surgery from January 2018 to June 2024 were retrospectively evaluated. Logistic regression analysis and backward stepwise method were used to detect independent predictors of preoperative DVT diagnosis in elderly patients with anemia who underwent total hip replacement surgery. A nomogram prediction model was established through multivariate logistic regression and subsequently utilized the testing group to validate.

Results: A multivariate logistic regression model was used to analyze the data, Hematocrit (HCT) (Odds ratio (OR) = 0.14, 95% confidence intervals (CI):[0.04,0.52]; P = 0.003), Albumin (ALB) (OR = 0.1, 95% CI:[0.03,0.37]; P = 0.001), Prothrombin Time (PT) (OR = 0.29, 95% CI:[0.1,0.83]; P = 0.02), Fibrin Degradation Products (FDP) (OR = 0.15, 95% CI:[0.05,0.49]; P = 0.002) and lymphocyte/Monocyte ratio (LMR) (OR = 0.28, 95% CI:[0.09,0.87], P = 0.028) were independent predictors for DVT before THA in elderly patients with anemia. The area under the curve (AUC) scores were 0.929 for the training group and 0.896 for the testing group, with calibration curve mean errors of 0.017 and 0.023, respectively. The decision curve analysis (DCA) graph indicates that the developed nomogram was highly practical and advantageous for clinical application.

Conclusion: The independent predictors of preoperative DVT in elderly anemic patients undergoing total hip replacement primarily include HCT, ALB, PT, FDP, and LMR at admission, which are easy to obtain and can quickly yield results. Moreover, the nomogram based on HCT, ALB, PT, FDP, and LMR can help clinical doctors evaluate the possibility of DVT formation, thereby accurately and quickly assisting clinical doctors in making better clinical judgments.