Development and External Validation of the Spinal Tumor Surgery Risk Index

BACKGROUND: Patients undergoing surgical procedures for spinal tumors are vulnerable to major adverse events (AEs) and death in the postoperative period. Shared decision making and preoperative optimization of outcomes require accurate risk estimation. OBJECTIVE: To develop and validate a risk index to predict short-term major AEs after spinal tumor surgery. METHODS: Prospectively collected data from multiple medical centers affiliated with the American College of Surgeons National Surgical Quality Improvement Program from 2006 to 2020 were reviewed. Multiple logistic regression was used to assess sociodemographic, tumor-related, and surgery-related factors in the derivation cohort. The spinal tumor surgery risk index (STSRI) was built based on the resulting scores. The STSRI was internally validated using a subgroup of patients from the American College of Surgeons National Surgical Quality Improvement Program database and externally validated using a cohort from a single tertiary center. RESULTS: In total, 14 982 operations were reviewed and 4556 (16.5%) major AEs occurred within 30 days after surgery, including 209 (4.5%) deaths. 22 factors were independently associated with major AEs or death and were included in the STSRI. Using the internal and external validation cohorts, the STSRI produced an area under the curve of 0.86 and 0.82, sensitivity of 80.1% and 79.7%, and specificity of 74.3% and 73.7%, respectively. The STSRI, which is freely available, outperformed the modified frailty indices, the American Society of Anesthesiologists classification, and the American College of Surgeons risk calculator. CONCLUSION: In patients undergoing surgery for spinal tumors, the STSRI showed the highest predictive accuracy for major postoperative AEs and death compared with other current risk predictors.