The Impact of Elixhauser Comorbidity Index and American Society of Anesthesiology Status on 90-day Readmission After Cervical and Lumbar Herniated Disc Surgery

Introduction: The Elixhauser (ELIX) comorbidity score categorizes patient comorbidities, while the American Society of Anesthesiology (ASA) physical status classification helps to assess whether a patient can tolerate anesthesia and surgery. Both of these metrics predict risks in patients undergoing surgery. However, no previous study has compared the utility of the ELIX score and the ASA score in predicting outcomes following surgery for cervical and lumbar herniated disc. Therefore, the objective was to compare if a point increase in ELIX score and the ASA score corresponds to the risk of 90-day readmission for patients after cervical and lumbar herniated disc surgery.

Methods: A retrospective database of 4,940 patients who underwent cervical and lumbar herniated disc surgery over 10 years at a single institution was analyzed. Demographic variables, preoperative variables, and ASA metrics were collected for all patients in this cohort. Multivariable Logistic Regression analysis was performed while controlling for demographic variables to evaluate the influence of ELIX and ASA scores on 90-day readmission.

Results: For the cervical cohort, every point increase in ELIX score was associated with 1.30 odds of 90-day readmission (OR=1.298;95%CI=1.126-1.491). Meanwhile, every point increase in ASA score was associated with 1.78 higher odds of 90-day readmission (OR=1.780;95%CI=1.103-2.894). For the lumbar cohort, every point increase in ELIX score was associated with 1.16 odds of 90-day readmission (OR=1.156;95%CI=1.021-1.304) and every point increase in ASA score was associated with 1.52 odds of 90-day readmission (OR=1.515;95%CI=1.119-2.051).

Conclusion : Both ASA and ELIX scores are associated with increased odds of 90-day readmission following cervical and lumbar herniated disc surgery. This finding may be useful in clinical practice as both ELIX scores and ASA could help preoperatively predict readmission risk following herniated disc surgery.