The risks, reasons, and costs for 30- And 90-day readmissions after fusion surgery for adolescent idiopathic scoliosis

OBJECTIVE With the continued evolution of bundled payment plans, there has been a greater focus within orthopedic surgery on quality metrics up to 90 days of care. Although the Centers for Medicare and Medicaid Services does not currently penalize hospitals based on their pediatric readmission rates, it is important to understand the drivers for unplanned readmission to improve the quality of care and reduce costs. METHODS The National Readmission Database provides a nationally representative sample of all discharges from US hospitals and allows follow-up across hospitals up to 1 calendar year. Adolescents (age 10–18 years) who underwent idiopathic scoliosis surgery from 2012 to 2015 were included. Patients were separated into those with and those without readmission within 30 days or between 31 and 90 days. Demographics, operative conditions, hospital factors, and surgical outcomes were compared using the chi-square test and t-test. Independent predictors for readmissions were identified using stepwise multivariate logistic regression. RESULTS A total of 30,677 patients underwent adolescent idiopathic scoliosis surgery from 2012 to 2015. The rates of 30- and 90-day readmissions were 2.9% and 1.4%, respectively. The mean costs associated with the index admission and 30- and 90-day readmissions were $60,680, $23,567, and $16,916, respectively. Common risk factors for readmissions included length of stay > 5 days, obesity, neurological disorders, and chronic use of antiplatelets or anticoagulants. The index admission complications associated with readmissions were unintended durotomy, syndrome of inappropriate antidiuretic hormone, and superior mesenteric artery syndrome. Hospital factors, discharge disposition, and operative conditions appeared to be less important for readmission risk. The top reasons for 30-day and 90-day readmissions were wound infection (34.7%) and implant complications (17.3%), respectively. Readmissions requiring a reoperation were significantly higher for those that occurred between 31 and 90 days after the index readmission. CONCLUSIONS Readmission rates were low for both 30- and 90-day readmissions for adolescent idiopathic scoliosis surgery patients. Nevertheless, readmissions are costly and appear to be associated with potentially modifiable risk factors, although some risk factors remain potentially unavoidable.