Associated risk factors for extended length of stay following anterior cervical discectomy and fusion for cervical spondylotic myelopathy

Objectives: There is a paucity of literature describing the predictors associated with extended length of hospital stay (LOS) for patients undergoing anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy. The aim of this study was to identify the patientand hospital-level factors associated with extended LOS for patients with cervical spondylotic myelopathy undergoing ACDF. Patients and methods: The National Inpatient Sample database was queried to identify patients with a diagnosis of cervical spondylotic myelopathy undergoing ACDF between 2010 and 2014. Updated trend weights were used to assess patient demographics, comorbidities, complications, LOS, discharge disposition and total cost. Multivariate logistic regression was used to determine the odds ratio for risk-adjusted LOS. The primary outcome was the degree to which patient comorbidities or postoperative complications correlated with extended LOS (> 3 days). Results: We identified 144,514 patients with 29,947 (20.7%) experiencing an extended LOS (Normal LOS: 114,567; Extended LOS: 29,947). Comorbidities were overall significantly higher in the extended LOS cohort compared to the normal LOS cohort. Patients with extended LOS had a significantly greater proportion of blood transfusion (p < 0.001) and 2-3 vertebral levels fused (p < 0.001). The overall complication rates were greater in the extended LOS cohort (Normal LOS: 7.4% vs. Extended LOS: 44.8%, p < 0.001). The extended LOS cohort incurred $14,489 more in total cost (Normal LOS: $15,486 [11,787-20,623] vs. Extended LOS: $29,975 [21,286-45,285], p < 0.001) and had more patients discharged to non-routine locations (p 0.001) compared to the normal LOS cohort. On multivariate logistic regression, several risk-factors were associated with extended LOS including: age, male gender, Black and Hispanic race, patient income, insurance, multiple co morbidities, blood transfusion, and number of complications. The odds ratio for extended LOS was 5.15 (95% CI: 4.68-5.67) for patients with 1 complication and 25.54 (95% CI: 20.54-31.75) for patients with 1 complication. Conclusion: Our national cohort study demonstrated multiple patientand hospital-level factors associated with extended LOS (> 3 days) after ACDF for CSM. Specifically, patients with an extended LOS had lower socioeconomic status, higher rate of comorbidities, greater percentage of postoperative complications and non -routine discharges, with greater overall costs. Further investigational studies are necessary to identify quality improvement strategies targeted to better optimizing patients preoperatively and reducing perioperative complications in order to improve quality of patient care and reduce hospital LOS.