Spine trauma and spinal cord injury in Utah: a geographic cohort study utilizing the National Inpatient Sample

OBJECTIVE The objective of this study was to investigate the effect of hospital type and patient transfer during the treatment of patients with vertebral fracture and/or spinal cord injury (SCI). METHODS The National Inpatient Sample (NIS) database was queried to identify patients treated in Utah from 2001 to 2011 for vertebral column fracture and/or SCI (ICD-9-CM codes 805, 806, and 952). Variables related to patient transfer into and out of the index hospital were evaluated in relation to patient disposition, hospital length of stay, mortality, and cost. RESULTS A total of 53,644 patients were seen (mean [+/- SEMI age 55.3 +/- 0.1 years, 46.0% females, 90.2% white), of which 10,620 patients were transferred from another institution rather than directly admitted. Directly admitted (vs transferred) patients showed a greater likelihood of routine disposition (54.4% vs 26.0%) and a lower likelihood of skilled nursing facility disposition (28.2% vs 49.2%) (p < 0.0001). Directly admitted patients also had a significantly shorter length of stay (5.6 +/- 6.7 vs 7.8 +/- 9.5 days, p < 0.0001) and lower total charges ($26,882 +/- $37,348 vs $42,965 +/- $52,118, p < 0.0001). A multivariable analysis showed that major operative procedures (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.4-2.0, p < 0.0001) and SCI (HR 2.1, 95% CI 1.6-2.8, p < 0.0001) were associated with reduced survival whereas patient transfer was associated with better survival rates (HR 0.4, 95% CI 0.3-0.5, p < 0.0001). A multivariable analysis of cost showed that disposition (beta = 0.1), length of stay (beta = 0.6), and major operative procedure (beta = 0.3) (p < 0.0001) affected cost the most. CONCLUSIONS Overall, transferred patients had lower mortality but greater likelihood for poor outcomes, longer length of stay, and higher cost compared with directly admitted patients. These results suggest some significant benefits to transferring patients with acute injury to facilities capable of providing appropriate treatment, but also support the need to further improve coordinated care of transferred patients, including surgical treatment and rehabilitation.