Evaluation of American Society of Anesthesiologists classification as 30-day morbidity predictor after single-level elective anterior cervical discectomy and fusion

BACKGROUND CONTEXT: Higher American Society of Anesthesiologists (ASA) classification is a known predictor of postoperative complication in diverse surgical settings. However, its predictive value is not established in single-level elective anterior cervical discectomy and fusion (SLE-ACDF). PURPOSE: This study aimed to evaluate the predictive value of ASA classification system on 30-day morbidity following SLE-ACDF. DESIGN/SETTING: Patients who underwent SLE-ACDF between 2011 and 2013 were selected from the American College of Surgeons National Surgical Quality Improvement Program database. PATIENT SAMPLE: A total of 6,148 patients were selected from the 2011-2013 American College of Surgeons National Surgical Quality Improvement Program database. OUTCOME MEASURES: All outcomes are self-report measures as tracked by dedicated clinical reviewers via prospective review of inpatient charts, outpatient clinic visits, and direct contact with the surgical team. METHODS: Propensity score matching and multiple logistic regression analyses were performed to evaluate ASA classification as 30-day morbidity predictor. This study has no financial conflict and has no potential conflict of interest to disclose. RESULTS: A total of 6,148 patients were analyzed in this study. Patients in the ASA >II cohort had higher incidence of comorbidities and postoperative complications (overall complication, pneumonia, unplanned intubation, ventilator dependent >48 hours, cerebrovascular accident or stroke, catastrophic outcome, and airway complication). Propensity score matching yielded 1,628 pairs of well-matched patients. Multivariable analyses with the propensity score matched dataset revealed the following associations between ASA class >II and 30-day outcomes: any complication (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.48-1.41), pneumonia (OR 1.22, 95% CI 0.33-4.56), unplanned intubation (OR 1.49, 95% CI 0.41-5.36), ventilator >48 hours (OR 5.92, 95% CI 0.69-50.96), catastrophic outcome (OR 1.02, 95% CI 0.39-2.71), and airway complication (OR 2.21, 95% CI 0.67-7.29). CONCLUSIONS: Although we did not detect associations between ASA class > II and adverse 30day outcomes following SLE-ACDF, imprecision of estimates precludes definitive inferences. Although ASAclassification allows simple assessment of patients' physiological status, their overall perioperative