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

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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).


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.


A total of 53,644 patients were seen (mean [± SEM] 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 (β = 0.1), length of stay (β = 0.6), and major operative procedure (β = 0.3) (p < 0.0001) affected cost the most.


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.

ABBREVIATIONS CI = confidence interval; HR = hazard ratio; ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification; LOS = length of stay; NHS = National Health Service; NIS = National Inpatient Sample; SCI = spinal cord injury; SEM = standard error of the mean; SNF = skilled nursing facility.

Downloadable materials

  • Tables S1 and S2 and Fig.S1 (PDF 3.45 MB)

Article Information

Correspondence Andrew T. Dailey: University of Utah, Salt Lake City, UT. neuropub@hsc.utah.edu.

INCLUDE WHEN CITING Published online March 29, 2019; DOI: 10.3171/2018.12.SPINE18964.

Disclosures Dr. Bisson reports being the recipient of a grant from PCORI, receiving fellowship funding from Globus, and having stock ownership in and a consultant relationship with nView. Dr. Dailey reports receiving research funding from K2M and being a consultant for Medtronic, K2M, and Zimmer-Biomet.

© AANS, except where prohibited by US copyright law.



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    Patient transfer and outcomes after vertebral body fracture and/or SCI in Utah. A: Increased transfer of patients was seen in later years, from 2008 to 2011, compared with prior years. Variation in the number of admitted patients was seen because of hospital sampling changes each year in the NIS. B: Routine disposition (e.g., home or home health) was significantly higher for admitted patients than for transferred patients (54.4% vs 26.0%, *p < 0.0001). C: Admitted patients had a slightly higher mortality rate than transferred patients (2.9% vs 1.9%). D: Significantly higher charges were seen for transferred patients than admitted patients ($30,100 ± $203 vs $45,707 ± $539, *p < 0.0001). Values are expressed as mean ± SEM. Figure is available in color online only.




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