IntroductionChronic kidney disease (CKD) has an increasing global prevalence and has previously been associated with increased complications and morbidity after spine surgery. Understanding the isolated effect of CKD on short-term patient outcomes is critical for optimizing perioperative risk management and healthcare utilization. ObjectiveThe aim of this study is to utilize coarsened exact matching (CEM) to analyze the isolated effect of CKD on short-term patient outcomes in single-level posterior lumbar fusion surgery. MethodsA retrospective analysis of 4680 consecutive patients undergoing single-level, posterior-only lumbar fusion was performed. Univariate logistic regression comparing the odds of outcomes in patients with CKD (n=40) to patients without medical comorbidities (n=2329) was performed. CEM was then employed to match patients with CKD to those without any comorbidities 1:1 on ten patient characteristics known to affect neurosurgical outcomes. Primary outcomes included intraoperative complications, length of stay, discharge disposition, and 30-day Emergency Department (ED) visits, readmissions, reoperations, and mortality. ResultsIn a univariate logistic regression, CKD was associated with increased risk of 30-day ED visits (OR=3.53, p=0.003) but not complication, discharge disposition, or 30-day readmissions or reoperations. Between otherwise exactly matched patients (n=72), CKD similarly remained associated with an increased risk of 30-day ED visits (OR=7.00, p=0.034) and not with other outcomes. ConclusionBetween otherwise exactly matched patients undergoing single-level posterior lumbar fusion, CKD was related to increased risk of 30-day ED utilization but not other markers indicative of inferior surgical outcomes. Further study must investigate the reasons for increased ED visitation and implement risk-mitigation strategies for these patients.