BackgroundIntraoperative autologous transfusion (IAT) has been used in scoliosis surgery for decades; however, its cost-effectiveness remains debatable. This study aimed to evaluate the cost-effectiveness of IAT in adolescent idiopathic scoliosis (AIS) surgery and identify risk factors of massive intraoperative blood during this surgery.MethodsThe medical records of 402 patients who underwent AIS surgery were reviewed. The patients were divided into different groups according to the intraoperative blood loss volume (group A: ≥500 to < 1000 mL, B: ≥1,000 to < 1,500 mL, and C: ≥1,500 mL) and whether IAT was used (i.e., IAT and no-IAT groups). The volume of blood loss, volume of transfused allogeneic red blood cells (RBC), and RBC transfusion costs were analysed. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors of massive intraoperative blood loss (≥ 1,000 mL and ≥ 1,500 mL). A receiver operating characteristic (ROC) curve was used to analyse the cut-off values of the factors contributing to massive intraoperative blood loss.ResultsIn group A, no significant difference was observed in the volume of allogeneic RBC transfused during and after procedure between the IAT and no-IAT groups; however, total RBC transfusion costs was significantly higher in the IAT group. In groups B and C, the patients in the IAT group compared with those in the no-IAT group had a lower volume of allogeneic RBC transfused during the operation and on the first day after the operation. However, in group B, the total RBC transfusion cost in the patients who used IAT was significantly higher. In group C, total RBC transfusion cost in the patients who used IAT was significantly lower. The number of fused vertebral levels and Ponte osteotomy were found to be independent risk factors for massive intraoperative blood loss. ROC analysis showed that more than eight and 10 fused vertebral levels predicted ≥ 1,000 mL and ≥ 1,500 mL intraoperative blood loss, respectively.ConclusionThe cost-effectiveness of IAT in AIS was related to the volume of blood loss, and when the blood loss volume was ≥ 1,500 mL, IAT was cost-effective, drastically reducing the demand for allogeneic RBC and total RBC transfusion cost. The number of fused vertebral levels and Ponte osteotomy were independent risk factors for massive intraoperative blood loss.