Sat., 10/6/12 General Interest, PAPER #103, 2:07 pm OTA-2012
The Influence of Insurance Status on the Surgical Treatment of Acute Spinal Fractures
Michael C. Daly, MSc; S. Samuel Bederman, MD, PhD, FRCSC;
University of California, Irvine Medical Center, Department of Orthopaedic Surgery,
Orange, California, USA
Background/Purpose: Fractures to the spinal column can be devastating injuries and those associated with spinal cord injuries are frequently treated emergently. Spinal fractures are often treated with surgical management based on fracture stability and the presence of neurologic involvement. Other factors, apart from fracture location, the presence of spinal cord injury, or other associated injuries may influence the decision for surgical intervention. It is poorly understood how nonclinical factors, such as insurance status, influence the decision for surgical intervention in these injuries. The purpose of this study was to determine the influence of insurance status on the rate of surgical intervention for acute cervical and thoracolumbar spine fractures with and without neurologic deficit.
Methods: Using data from the National Trauma Data Bank collected from January 2008 through December 2009, we included all patients age 18 to 64 who sustained a fracture of the cervical or thoracolumbar spine. Patients were excluded if they were dead on arrival or died in the emergency department, or if they sustained polytrauma (ISS ≥27) or a major injury (Abbreviated Injury Scale severity ≥3) to the head, thorax, or abdomen. Our main outcome measure was operative versus nonoperative treatment; our main predictor was insurance status. We analyzed baseline variables using bivariate statistics for our unadjusted comparisons. To control for the observed confounders in our adjusted comparisons, we calculated a propensity score representing the likelihood of each patient having insurance. Propensity scores were derived from a multivariable logistic regression model controlling for clinical (fracture location, spinal cord injury, comorbidities, demographics, mechanism of injury, and injury severity) and nonclinical factors (transfer status and hospital characteristics). Using hierarchical multivariable logistic regression models to account for clustering by hospital facility, we determined adjusted odds ratios (OR) for rate of surgery controlling for propensity score, insurance status, and clinical and nonclinical factors.
Results: We identified 40,316 spine fracture patients (mean age 40 years, 69% male, 77% white). In our unadjusted comparisons, surgery was associated with insurance (OR: 1.29, P <0.0001) and spinal cord injury (OR: 8.71, P <0.0001), as well as cervical (OR: 1.25, P <0.0001) and multilevel (OR: 1.13, P = 0.0080) fractures relative to thoracolumbar fractures. After accounting for clustering by hospital and controlling for propensity score and hospital nonprofit status, hierarchical logistic regression models demonstrated significantly higher rates of surgery in patients with insurance (OR: 1.31, P <0.0001), spinal cord injury (OR: 10.40, P <0.0001), blunt trauma (OR: 4.83, P <0.0001), shock (OR: 1.51, P <0.0001), younger age (OR: 1.004, P = 0.0023), higher Glasgow Coma Scale score (OR: 1.02, P = 0.0135), transfer from lower acuity hospital (OR: 1.62, P <0.0001), and those treated at teaching hospitals (OR: 1.41, P = 0.0428). Race, gender, comorbidity, and fracture location were not statistically associated with higher surgical rates. Multivariable subgroup analysis of patients with spinal cord injury similarly revealed higher surgical rates for insured patients (OR: 1.32, P = 0.0331).
Conclusion: Patients with traumatic spine fractures were more likely to receive surgery if they were insured, regardless of the presence of neurologic injury or fracture location. Further studies are needed to identify potentially modifiable factors influencing the decision for surgery and improve disparities in the delivery of health-care services.
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• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.