Safety of outpatient

Objective: To evaluate and compare the safety of outpatient and inpatient anterior cervical discectomy and fusion (ACDF) regarding complications and related outcomes. Methods: PubMed, Embase, and Scopus were systematically searched for retrospective cohort studies published between January 1, 2000, and December 31, 2024, comparing outpatient and inpatient ACDF. Pooled relative risks (RRs) and weighted mean differences (WMDs) were calculated using a random-effects model. Study quality and certainty of evidence were assessed using the Newcastle-Ottawa Scale (NOS) and GRADE, respectively. Results: A total of 21 studies involving 164,541 patients (36,361 outpatient and 128,180 inpatient) were included. Outpatient ACDF resulted in significantly lower incidence of overall complications (RR 0.45, 95% CI [0.35-0.57]), mortality (RR 0.35, 95% CI [0.16-0.77]), deep vein thrombosis (RR 0.56, 95% CI [0.37-0.85]), and wound complications (RR 0.59, 95% CI [0.52-0.68]). Reduced risks were also observed for unplanned reoperations (RR 0.33, 95% CI [0.24-0.46]), readmissions (RR 0.57, 95% CI [0.46-0.70]), and pulmonary complications (RR 0.43, 95% CI [0.27-0.68]). Risks of stroke, dysphagia, hematoma, and renal and cardiac complications were comparable between the groups. The certainty of evidence was rated low to very low due to high heterogeneity, retrospective study designs, and indirectness. Conclusion: Outpatient ACDF is associated with fewer complications as compared to inpatient procedures for carefully selected patients. However, the retrospective nature of the studies, the possibility of selection bias, and low-certainty evidence underscore the need for high-quality prospective research to validate these results and inform clinical practice.