Validity of E-PASS System for Postoperative Morbidity of Spinal Surgery

STUDY DESIGN: A single-center retrospective cohort study. OBJECTIVE: To evaluate the ability of the Estimation of Physiologic Ability and Surgical Stress (E-PASS) system to predict postoperative risk in patients scheduled for spinal surgery. SUMMARY OF BACKGROUND DATA: The E-PASS system is a surgical audit to predict postoperative morbidity and mortality in general surgery. It is currently not applied in patients with spinal disorders. METHODS: The E-PASS system is comprised of a preoperative risk score (PRS), a surgical stress score (SSS), and a comprehensive risk score (CRS). The latter reflects both the PRS and SSS. We calculated the E-PASS scores for 275 consecutive patients who underwent spinal surgery and evaluated the relationship between the incidence of postoperative complications and each score of the E-PASS system and their ability to predict postoperative morbidity. RESULTS: Postoperative complications developed in 31 patients (11.3%). All E-PASS scores were significantly higher in patients with postoperative complications and they were linearly correlated with the overall incidence of postoperative complications. In particular, PRS was correlated with complications at nonsurgical sites and SSS with surgical site complications. The area under the receiver operating characteristic curve (AUC) for PRS and SSS was higher in patients with complications at nonsurgical and surgical sites, respectively. The AUC for CRS exhibited good predictive power for both types of complication. CONCLUSIONS: The E-PASS system correctly predicted morbidity. The predictive ability of CRS was good for overall morbidity. The E-PASS system is useful for the accurate prediction of the risk for in-hospital morbidity in individual patients scheduled for spinal surgery.