Utility of Readmission Rates as a Quality of Care Measure and Predictors of Readmission Within 30 Days After Spinal Surgery: A Single-Center, Multivariate Analysis

Study Design. A retrospective review Objective. The aim of this study was to establish clinically relevant readmission rates that permit accurate comparisons, improve risk-stratification, and direct efforts to minimize readmissions. Summary of Background Data. The 30-day hospital readmission rate is a quality of care measure that is now being used to compare hospitals in a publicly available manner. Methods. Records from 1187 consecutive spinal surgeries at Northwestern Memorial Hospital in 2010 were retrospectively reviewed and data were collected that described the patient, surgical procedure, hospital course, complications, and readmissions. The primary outcome of interest was readmission to the hospital within 30 days. Potential risk factors were examined for association with the outcome first via bivariate analysis, with significant predictors further examined by a multivariable model. Identified readmissions were independently reviewed by attending spinal neurosurgeons not involved with the cases to determine whether the readmissions were procedure related or procedure unrelated with respect to accepted criteria. Results. The overall readmission rate was 6.1%. Of these readmissions, 37.5% were deemed procedure related upon attending review, leading to a procedure-related readmission rate of 2.3%. Upon multivariate analysis, only 3 variables were found to be significant predictors of readmission: 2 or more patient comorbidities [odds ratio (OR) 3.72, 95% confidence interval (95% CI) 1.62-8.56], an admission to the ICU (OR 2.68, 95% CI 1.45-4.95), and each additional spinal level involved (OR 1.11, 95% CI 1.02-1.21). Conclusions. Our study suggests that predictors for all-cause 30-day readmission following spinal procedures include number of spinal levels performed during the surgery, number of patient comorbidities present at the time of surgery, and whether the admission required an ICU stay. Future work should focus on developing best practices to modify medical risk factors and comorbidities that have the potential to decrease 30-day readmission rates.