National rates, causes, risk factors, and outcomes associated with 30-day and 90-day readmissions following degenerative posterior cervical spine surgery utilizing the nationwide readmissions database

BACKGROUND: Hospital readmissions have profound financial and clinical impacts. Analyses of 30-day readmissions following spine surgery have been previously reported utilizing administrative databases. However, time periods outside the initial 30 days have not been well studied. Furthermore, these databases have limitations regarding coding and institutional crossover. OBJECTIVE: The authors sought to analyze 30-day and 90-day readmission rates and risk factors using the Nationwide Readmissions Database (NRD) in a retrospective cohort receiving elective, posterior cervical spine surgery for degenerative conditions. METHODS: NRD is a new source containing approximately 50% of US hospitalizations, with patient-linkage numbers to longitudinally track patients. Patients 18 years of age or older were identified. Preoperative characteristics, demographics, and surgical characteristics were chosen for predictor variables. Thirty-day and 90-day readmission rates were calculated. Statistical analysis was completed using SPSS v.23 software via univariate and multivariate analyses. RESULTS: Between January and September 2013, a total of 29 990 patients were identified. Readmission rates for 30- And 90-days were 5.4% and 10.0%, respectively. The most common reason for readmission during 30-day and 90-day periods was complications of surgical and/or medical care (31.0% vs 21.9%, respectively). The strongest risk factors for 30- day readmission includedwound dehiscence,weekend admission at index hospitalization, coagulopathy, and incidental durotomy. The strongest risk factors for 90-day readmission included thromboembolic complications, postoperative hemorrhage, and comorbidities. CONCLUSION: Identification of predictors of readmission is important to allowfor changes in perioperative management to potentially reduce readmissions and improve outcomes. Additionally, knowledge about readmission risk factors allows for preoperative counseling.