Comparative Analysis of 30-Day Readmission, Reoperation, and Morbidity between Posterior Cervical Decompression and Fusion Performed in Inpatient and Outpatient Settings

Study Design: A retrospective cohort study. Purpose: To compare 30-day readmission, reoperation, and morbidity for patients undergoing posterior cervical decompression and fusion (PCDF) in inpatient vs. outpatient settings. Overview of Literature: PCDF has recently been increasingly performed in outpatient settings, often utilizing minimally invasive techniques. However, literature evaluating short-term outcomes for PCDF is scarce. Moreover, no currently large-scale database studies have compared short-term outcomes between PCDF performed in the inpatient and outpatient settings. Methods: Patients who underwent PCDF from 2005 to 2018 were identified using the National Surgical Quality Improvement Program database. Regression analysis was utilized to compare primary outcomes between surgical settings and evaluate for predictors thereof. Results: We identified 8,912 patients. Unadjusted analysis revealed that outpatients had lower readmission (4.7% vs. 8.8%, p=0.020), reoperation (1.7% vs. 3.8%, p=0.038), and morbidity (4.5% vs. 11.2%, p<0.001) rates. After adjusting for baseline differences, readmission, reoperation, and morbidity no longer statistically differed between surgical settings. Outpatients had lower operative time (126 minutes vs. 179 minutes) and levels fused (1.8 vs. 2.2) (p<0.001). Multivariate analysis revealed that age (p=0.008; odds ratio [OR], 1.012), weight loss (p=0.045; OR, 2.444), and increased creatinine (p<0.001; OR, 2.233) independently predicted readmission. The American Society of Anesthesiologists (ASA) classification of ≥3 predicted reoperation (p=0.028; OR, 1.406). Rehabilitation discharge (p<0.001; OR, 1.412), ASA-class of ≥3 (p=0.008; OR, 1.296), decreased hematocrit (p<0.001; OR, 1.700), and operative time (p<0.001; OR, 1.005) predicted morbidity. Conclusions: The 30-day outcomes were statistically similar between surgical settings, indicating that PCDF can be safely performed as an outpatient procedure. Surrogates for poor health predicted negative outcomes. These results are particularly important as we continue to shift spinal surgery to outpatient centers. This importance has been highlighted by the need to unburden inpatient sites, particularly during public health emergencies, such as the coronavirus disease 2019 pandemic.