Analysis of short- and delayed unplanned readmission rates after anterior discectomy and fusion for CSM

Introduction: Many patients with cervical spondylotic myelopathy (CSM) undergo anterior cervical discectomy and fusion (ACDF). Many of these patients are readmitted, but there is no clear understanding of drivers of readmission. The aim of this study was to assess the patient- and hospital-level factors that contribute to 7-, 30-, and 90-day readmissions after treatment of CSM.

Methods: A retrospective cohort study was performed using the 2016-2019 Nationwide Readmissions Database (NRD). All adult patients undergoing ACDF for CSM were identified using ICD-10 coding. Patients were stratified by no readmission, readmission within 7 days, readmission within 8-30 days, or readmission within 31-90 days. Patient demographic information, comorbidities, and adverse events were collected.

Results: Of the 19,621 patients included, 576 were readmitted within 7 days, 568 within 30, 794 within 90, and 17,683 who were not readmitted. The patients readmitted within 7 and 30 days were significantly older than the 90-day patients, who were older than the non-readmitted patients (p < 0.001) and had a higher frailty score by the modified frailty index (p < 0.001). The 30-day readmission cohort had the longest mean LOS (p < 0.001) and the greatest mean total admission costs (p < 0.001). Drivers of readmission included sepsis, infection, and acute kidney failure.

Conclusion: Our study found that the most common diagnoses during readmission included sepsis and other infection for 7-, 30-, and 90-day readmission for CSM patients who underwent ACDF. Further studies are needed to understand how to decrease likelihood for readmission.