Regional Variations in Cost of Trauma Care in the United States: Who is Paying More?

Background: The study of regional variations in costs of care has been used to identify areas of savings for several diseases and conditions. This study investigates similar potential regional differences in the cost of adult trauma care using an all-payer, nationally representative sample.

Methods: Trauma patients aged 18 to 64 years in the 2006-2008 Nationwide Inpatient Sample were identified using International Classification of Diseases, 9th Revision, Clinical Modification codes. Those with isolated diagnoses for five index conditions (ICs): blunt splenic injury, liver injury, tibia fracture, moderate traumatic brain injury, and pneumothorax/hemothorax were selected. Cost was estimated from charges using a cost-to-charge ratio. Generalized linear modeling was used to compare the mean cost for treating these ICs between US regions (Northeast, South, Midwest, and West), adjusting for hospital factors (size, teaching status, and location), patient demographics, injury severity, length of stay, Charlson comorbidity index, local wage index, and payer. Relative mean cost (RC) was calculated using Northeast as the reference, and sampling weights were applied to obtain regional estimates. Differences in adjusted mortality between regions were also assessed.

Results: Adjusted relative costs were estimated for 62,678 patients (South: 28,536; West: 12,975; Midwest: 11,450; and Northeast: 9,717). Mean costs for liver injury were 22%higher in the Midwest compared with the Northeast (RC: 1.22; 95%confidence interval [CI]: 1.10-1.35). Similarly higher costs were seen with other regions and ICs (RC for blunt splenic injury in the South: 1.18; 95% CI: 1.07-1.31; RC for pneumothorax/hemothorax in the West: 1.31; 95% CI: 1.22-1.41). No differences in adjusted mortality by region were noted overall.

Conclusion: Even after controlling for factors known to influence medical care cost, as well as controlling for geographic differences in pricing, significant regional differences exist in the cost of trauma care. Exploring these variations may assist in identifying potential areas for cost savings.