This study examined potential inequalities in mortality among trauma victims in Texas. Regardless of the type and severity of an injury, the odds of death were statistically significantly associated with the victim's race/ethnicity and health insurance status. Even among those with health insurance coverage, the odds of mortality from trauma differed by the type of health insurance.
Previous studies have reported disparities in trauma outcomes based on race and health insurance [10, 12, 20–22]. However, several of these studies excluded a subgroup of the population from their analysis, which renders the generalization of their conclusions to be limited. For instance, because of access to Medicare and Medicaid, Haider  (2008) and Arthur  excluded patients aged < 18 years and ≥ 65 years from their analysis. Greene  also excluded patients with injuries from burns in addition to those aged ≥ 65 years. Our study improved on this limitation by including injury victims of all ages and types. Similarly, by categorizing the health insurance status of the trauma victim into the three groups (private, public, and the uninsured), we avoided excluding any demographic subgroup.
In this analysis, all the potential confounders remained statistically significantly associated with trauma mortality after the multivariate analysis. Our findings are consistent with and reinforce results from similar studies. [20–24]. Analyzing the unadjusted data, we found that trauma victims who were categorized as NHW more likely to be insured (both private and public). However, after the stratified (effect medication) analysis, we found that regardless of the insurance category, racial minorities (Hispanics and NHBs) had odds of mortality significantly higher than NHW trauma victims. Therefore, the observed disparity in trauma mortality could not be completely explained by the higher likelihood of being insured observed among the NHW trauma victims.
Another possible reason that could explain the observed disparities relates to the notion that uninsured patients are less likely to comply with their medications and keep follow-up appointments . Advocates of this notion argue that lack of treatment compliance (among the uninsured) may explain the observed disparities in the outcome of patients . However, as a counterargument, we know that urgent intervention (as opposed to long-term follow-up) is required to prevent mortality for trauma patients. Therefore, a possible lack of treatment and follow-up compliance (among uninsured trauma patients) is not enough to explain the observed disparities.
Still, it is unlikely that a trauma victim would be refused treatment or offered sub-standard care because of his/her demographics or insurance coverage . However, these (racial and insurance coverage) considerations may come into play after the victim is stabilized and ready for further management . Selassie  reported that uninsured and racial minorities were less likely to be hospitalized (but treated and released) after the initial ED care, despite having similar injuries proportionate in severity with those who were insured or non-racial minorities [13, 26, 27].
Additional explanations suggested for the observed health insurance-related mortality disparities relate to the health behavior pattern of patients [28, 29]. Kronick  argued that baseline (pre-disease or pre-injury) characteristics or behavior of a person might confound the relationship between health insurance-related access and mortality. Factors such as marital status, smoking habit, and Body Mass Index (BMI) were reported by Kronick  to be significant predictors of all-cause mortality in a population survey. According to Kronick , if these factors were to be adequately adjusted for, the risk of death between insured and uninsured would be the same. However, while we concede that social and behavioral factors such as cigarette smoking or marital status may influence mortality in general, we believe their influence is more significant in the outcomes of patients with chronic conditions, not for injury victims. Additionally, controlling for comorbid conditions in this analysis should reduce the confounding (if any) these factors may have introduced.
Systemic inequalities, perceived or real, often involve a complex interaction between access to resources, public policy, and social justice . While a causal relationship between access to health insurance and health outcomes is far from being established, several studies have reported evidence of racial minorities suffering a disproportionate burden of diseases and injuries because of factors beyond their control . In a previous work describing TBI-related hospitalization in Texas, Gwarzo , found Hispanic TBI patients had 80% higher odds of in-hospital mortality than their white comparison group even after adjusting for patient and hospital factors. Promoting health equity requires careful understanding of the barriers to optimum health, often such obstacles are modifiable through a review or change in public policy direction .
Findings from this study raise fundamental questions regarding access and quality of care available to trauma victims in Texas. With almost five million residents without health insurance coverage, Texas has both the highest number and proportion of uninsured of any U.S. state . The decision by Texas authorities not to expand Medicaid under the Affordable Care Act (ACA) has increased the uninsured coverage gap in Texas to the highest in the nation . Over a million Texans could be eligible for public insurance if Medicaid were to be expanded. In addition, Chen , found that low-income minorities were more likely to be uninsured in Texas, implying that improving access to this subgroup could help significantly in reducing the observed disparities in trauma-related mortality . Even though this study used data from Texas, we believe our findings are generalizable nationwide, however, we recommend the use of national data while maintaining similar methodology for future studies.
This study is not without some limitations. First, because data on the location of death was not available, we have no way of knowing whether the recorded mortality occurred at the point of care or otherwise. It is possible that more uninsured and racial minorities died before arriving point of care than their respective reference group. Additionally, we excluded patients who did not have a recorded method of payment and those with no race/ethnicity identity in the registry. However, because the proportion of trauma-related mortality was similar between those excluded in the analysis and those included, we do not believe the results were affected by excluding these patients. Finally, our study could still be influenced by residual confounding from factors not adequately measured in the data.