Outpatient Versus Inpatient Posterior Lumbar Fusion for Low-Risk Patients: An Analysis of Thirty-Day Outcomes From the National Surgical Quality Improvement Program

Outpatient spine surgery has been increasingly used recently owing to its perceived cost benefits and its ability to offset the volume from the inpatient setting. However, the 30-day outcomes of outpatient posterior lumbar fusion (PLF) for low-risk patients have not been extensively studied. In the present study, we assessed the 30-day outcomes of outpatient PLF surgery for low-risk patients using a national surgical quality registry. For the present study, we queried the American College of Surgeons National Surgical Quality Improvement Program for patients who had undergone PLF from 2009 to 2016. Only patients with an American Society of Anesthesiologists grade of 1–2 were included. The 30-day outcomes, including any complications, readmissions, and reoperations, were studied using multivariable logistic regression after adjustment for an array of patient-specific factors. A total of 29,830 cases were identified. Of these 29,830 cases, 1016 (3.4%) had been performed as outpatient cases and 28,814 (96.6%) as inpatient. After adjusting for an array of patient-specific factors, we did not find any significant association between the procedure setting and complication rate (odds ratio [OR], 0.8; 95% confidence interval [CI], 0.6–1.1; P = 0.15) or 30-day readmission rate (OR, 0.9; 95% CI, 0.6–1.4; P = 0.76). Patients undergoing outpatient PLF were more likely to have required a 30-day reoperation (OR, 1.6; 95% CI, 1.1–2.4; P = 0.02). Our results have demonstrated that the 30-day outcomes of patients who have undergone outpatient PLF might be comparable to those of patients who have undergone PLF in an inpatient setting. However, outpatient surgery might be associated with a greater overall reoperation rate.