Outpatient and inpatient readmission rates of 3- and 4-level anterior cervical discectomy and fusion surgeries

: OBJECTIVE With the costs related to the United States medical system constantly rising, efforts are being made to turn traditional inpatient procedures into outpatient same-day surgeries. In this study the authors looked at the various comorbidities and perioperative complications and their impact on readmission rates of patients undergoing outpatient versus inpatient 3- and 4-level anterior cervical discectomy and fusion (ACDF). METHODS This was a retrospective study of 337 3- and 4- level ACDF procedures in 332 patients (5 patients had both primary and revision surgeries that were included in this total of 337 procedures) between May 2012 and June 2017. In total, 331 procedures were analyzed, as 6 patients were lost to follow-up. Outpatient surgery was performed for 299 procedures (102 4-level procedures and 197 3-level procedures), and inpatient surgery was performed for 32 procedures (11 4-level procedures and 21 3-level procedures). Age, sex, comorbidities, number of fusion levels, pain level, and perioperative complications were compared between both cohorts. RESULTS Analysis was performed for 331 3- and 4-level ACDF procedures done at 6 different hospitals. The overall 30-day readmission rate was 1.2% (outpatient 3 [1.0%] vs inpatient 1 [3.1%], p = 0.847). Outpatients had increased readmission risk, with comorbidities of coronary artery disease (OR 1.058, p = 0.039), autoimmune disease (OR 1.142, p = 0.006), diabetes (OR 1.056, p = 0.001), and chronic kidney disease (OR 0.933, p = 0.035). Perioperative complications of delirium (OR 2.709, p < 0.001) and surgical site infection (OR 2.709, p < 0.001) were associated with increased risk of 30-day hospital readmission in outpatients compared to inpatients. CONCLUSIONS This study demonstrates the safety and effectiveness of 3- and 4-level ACDF surgery, although various comorbidities and perioperative complications may lead to higher readmission rates. Patient selection for outpatient 3- and 4-level ACDF cases might play a role in the safety of performing these procedures in the ambulatory setting, but further studies are needed to accurately identify which factors are most pertinent for appropriate selection.