Abstract: Objective In this article, we discussed the effect of preoperative anemia on perioperative blood transfusion and clinical outcomes in patients undergoing orthopedic surgery. Methods 33 379 hospitalized patients who underwent orthopedic surgery from January 2014 to January 2019 were selected as the survey subjects, and preoperative anemia was used as an independent variable to compare the effect of different degrees of anemia on perioperative blood transfusion and clinical outcomes by propensity score matching (PSM).Results After PSM, 34.5% of patients with mild anemia and 41.75% of patients with moderate to severe anemia had longer hospital stay (LOS≥12 d), and their perioperative red blood cell infusion rates were 58.24% and 73.34%, respectively. The ICU occupancy rates of the two groups were 2.84% and 4.97%, and the median hospitalzation expenses were ¥74 035.26 and ¥74 589.56 respectively, which were significantly higher than those of non-anemia group (P<0.001). The incidence of complications in patients with mild and moderate to severe anemia was 5.18% and 5.98%, respectively, which were significantly higher than those in non-anemia patients (P<0.05).Conclusions The preoperative anemia in patients undergoing orthopedic surgery could prolong their hospital stay, increase the perioperative blood transfusion rate and blood transfusion volume, and at the same time which could lead to a rise in ICU admission rate, hospitalization costs and postoperative complications.

Key words: Preoperative anemia, Blood transfusion, PSM, Orthopedics