Background: Lack of health care insurance has been correlated with increased mortality after trauma. Medical comorbidities significantly affect trauma outcomes. Access to health care and thereby being diagnosed with a pretrauma comorbidity is highly dependent on insurance status. The objective of this study was to determine whether rates of diagnosed or undiagnosed preexisting comorbidities significantly contribute to disparities in mortality rates observed between insured and uninsured trauma patients.
Methods: Review of trauma patients admitted to a Level I trauma center during a 5-year period. Data extracted from the registry included age, sex, Injury Severity Score (ISS), comorbidities, mortality, and insurance status. Multivariate logistic regression analysis was performed using age, sex, and insurance status to predict comorbidities and age, sex, ISS, and insurance status to predict mortality.
Results: Insured patients were older (54 years vs. 38, p < 0.001) and more likely female (41.3% vs. 22.5%, p < 0.001). When adjusting for age and sex, insured patients were more likely to have a pretrauma diagnosis of coronary artery disease (odds ratio [OR], 2.09; 95% confidence interval [CI], 1.54-2.83), diabetes mellitus (OR, 2.09; 95% CI, 1.61-2.72), hypertension (OR, 1.97; 95% CI, 1.65-2.35), asthma/emphysema (OR, 1.64; 95% CI, 1.32-2.04), neurologic problems (OR, 1.79; 95% CI, 1.31-2.44), and gastroesophageal reflux disease (OR, 2.03; 95% CI, 1.33-3.11), compared with patients without insurance. In the analysis to predict mortality, having insurance was protective (OR, 0.57; 95% CI, 0.45-0.71). Among patients with no diagnosed comorbidities, insured patients had the lowest mortality risk (OR, 0.5; 95% CI, 0.38-0.67). When analyzing only patients with diagnosed comorbidities, insurance status had no impact on mortality risk (OR, 0.81; 95% CI, 0.53-1.22).
Conclusion: Undiagnosed preexisting comorbidities play a crucial role in determining outcomes following trauma. Diagnosis of medical comorbidities may be a marker of access to health care and may be associated with treatment, which may explain the gap in mortality rates between insured and uninsured trauma patients.
Level of evidence: Prognostic/epidemiologic study, level III.