Identification of Risk Factors for Readmission in Patients Undergoing Anterior Cervical Discectomy Fusion: A Predictive Risk Scale.

ABSTRACT

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The objective of this study was to analyze readmission rates among patients undergoing anterior cervical discectomy and fusion (ACDF), determine which factors were associated with higher readmission rates, and develop a scale for utilization during surgical planning. SUMMARY OF BACKGROUND DATA ACDF is the most common surgical treatment for many cervical disk pathologies. With the Centers for Medicare and Medicaid Services selecting readmissions as a measure of health care quality, there has been an increased focus on reducing readmissions. MATERIALS AND METHODS: There were 114,174 recorded ACDF surgeries in the derivation cohort, the State Inpatient Database (SID) of New York and California between 2006 and 2014. There were 115,829 ACDF surgeries recorded in the validation cohort, the SID from Florida and Washington over the same time period. After identification of risk factors using univariate and multivariate analysis of the derivation cohort, a predictive scale was generated and tested utilizing the validation cohort. RESULTS: Overall, readmission rates within 30 days of discharge were 5.87% and 5.52% in the derivation and validation cohorts, respectively. On multivariate analysis of the derivation cohort, age older than 80 years [odds ratio (OR), 1.67] male sex (OR, 1.16), Medicaid insurance (OR, 1.90), Medicare insurance (OR, 1.64), revision ACDF (OR, 1.43), anemia (OR, 1.45), chronic lung disease (OR, 1.23), coagulopathy (OR, 1.42), congestive heart failure (OR, 1.31), diabetes (OR, 1.23), fluid and electrolyte disorder (OR, 1.56), liver disease (OR, 1.37), renal failure (OR, 1.59), and myelopathy (OR, 1.19) were found to be statistically significant predictors for readmission. These factors were incorporated into a numeric scale that, that when tested on the validation cohort, could explain 97.1% of the variability in readmission rate. CONCLUSIONS: Overall, 30-day readmission following ACDF surgery was 5%-6%. A novel risk scale based on factors associated with increased readmission rates may be helpful in identifying patients who require additional optimization to reduce perioperative morbidity. LEVEL OF EVIDENCE Level III-prognostic.