Factors contributing to perioperative blood transfusion during total hip arthroplasty in patients continuing preoperative aspirin treatment: a nomogram prediction model.

backgroundTotal hip arthroplasty (THA) is associated with considerable blood loss during the perioperative period, which commonly requires a blood transfusion, especially in patients who continue aspirin treatment preoperatively. Blood transfusion can significantly increase both the length of hospital stay and total treatment costs and is potentially associated with adverse reactions. However, a visual predictive model for assessing the risk of blood transfusion in THA patients is lacking. The aim of this study was to develop and validate a nomogram to predict the risk of blood transfusion during THA in patients who continue aspirin treatment preoperatively.

methodsFrom June 2016 to December 2022, 228 consecutive patients who continued preoperative aspirin treatment and underwent primary unilateral THA were enrolled in this retrospective study. Potential risk factors were screened using least absolute shrinkage and selection operator (LASSO) regression, and univariate and multifactorial logistic regressions were performed on the factors screened using LASSO regression to further control for confounding effects. Finally, a nomogram was constructed on the basis of the variables identified through multiple regression analysis. Internal validation was carried out using the Bootstrap method to assess the performance of the model using the C-index, area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA).

resultsAmong the 228 patients, 43 (18.9%) received a blood transfusion. Patients who received a blood transfusion had a longer hospital stay (p = 0.01). The independent risk factors for blood transfusion included the concomitant use of clopidogrel (OR = 4.415), preoperative hemoglobin level (OR = 0.062), total estimated blood loss volume (OR = 3.411), American Society of Anesthesiologists (ASA) class (OR = 1.274), and the use of tranexamic acid (OR = 0.348). The prediction model had a C-index of 0.862, an internally validated C-index of 0.833, and an AUC of 0.833, indicating excellent discriminatory power. The calibration curve showed a good calibration effect, and DCA indicated that the nomogram has strong clinical applicability.

conclusionsBased on these five independent risk factors, our nomogram can accurately predict the risk of blood transfusion in THA patients who continue aspirin treatment preoperatively, thereby assisting surgeons in clinical decision-making.