• Preoperative anemia is an independent risk factor for lower extremity deep vein thrombosis (DVT) after elective lumbar fusion, with an odds ratio of 4.221.
• The incidence of preoperative anemia was significantly higher in patients who developed DVT (32.6%) compared to those who did not (10.9%).
• D-dimer positivity was also identified as a significant risk factor for DVT, with an odds ratio of 2.023.
• The study recommends active management and correction of preoperative anemia to reduce the risk of DVT in patients undergoing elective lumbar fusion.