Patient Factors Contributing to Prolonged Postoperative Length of Stay and Increased Rate of Readmission after Elective Posterior Cervical Fusion

Study Design: This is retrospective study of prospectively collected data. Objective: To identify patient factors that are independently associated with prolonged length of stay (LOS) and readmission after posterior cervical fusion (PCF) utilizing a large national database. Summary of Background Data: A number of studies have investigated the morbidity and mortality after PCF; however, little is known about the factors that are associated with prolonged LOS and readmission, both of which incur increased costs for patients and hospitals. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2011 to 2014. Current Procedural Terminology code 22600 was used to identify patients who underwent PCF. All patient factors were assessed for association with LOS and readmission rate using bivariate and multivariate logistic regressions. Results: A total of 2667 patients who underwent PCF met the inclusion criteria for LOS analysis. Average (±SD) LOS was 3.92 (±3.24) days, and median LOS was 3 days (interquartile range, 2-5 d). On multivariate analysis, increased LOS was found to be significantly associated with dependent functional status (P<0.001), diabetes mellitus (P=0.021), preoperative anemia (P=0.001), American Society of Anesthesiologists class 3 or 4 (P<0.001), and number of fused levels (P<0.001). A total of 2591 patients met criteria (LOS≤11 d) for analysis of readmission. Readmission rate among these patients was 7.1%. Average (±SD) LOS of the patients not readmitted within 30 days of operation was 3.89 (±3.25), whereas the average (±SD) LOS of the patients readmitted was 4.24 (±3.08). On multivariate analysis, readmission was found to be significantly associated with only dependent functional status (P=0.019) and increased number of fused levels (P=0.032). Conclusions: The current study provides valuable information on patient factors that are associated with prolonged LOS and readmission, which would be useful in enhanced informed consent before surgery, surgical planning, discharge planning, and optimizing postoperative care. Level of Evidence: Level III.