302 Trends in Readmission Following Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis

INTRODUCTION: Many adolescents undergo posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) in the U.S. but require readmission in the weeks or months following discharge. METHODS: A retrospective cohort study was performed using the 2016–2019 Nationwide Readmissions Database (NRD). All adolescent patients undergoing PSF for AIS 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 12,289 patients, 0.53% underwent 7-Day readmission, 0.97% underwent 30-Day readmission, 0.33% underwent 90-Day readmission, and 98.2% underwent no readmission. The 90-Day readmission cohort had the oldest patients (p=0.012), and most patients were treated at urban non-teaching hospitals. The 30 and 90-day readmission cohorts had the highest proportion of people having 3 or more comorbidities, while the no readmission cohort had the highest % of those having 0 comorbidities. Clinically, postoperative adverse events were similar between cohorts, but hospital resource utilization differed, with the 30-day readmission cohort having the highest mean cost of admission at index admission. Postoperative pain was one of the greatest drivers of readmission for the 7-day readmission cohort but not the 30- or 90-day readmission groups. Having 3 or more comorbidities was associated with 7- and 30- day readmissions, while length of stay was associated with 30- and 90-day readmissions on multivariate analysis. CONCLUSIONS: This study describes the hospital readmissions following PSF for AIS, with number of comorbidities and initial length of stay likely being key contributors. Early readmissions included adolescent patients experiencing postoperative pain, whereas delayed readmissions were seen in patients with greater comorbidities.