Care without coverage: is there a relationship between insurance and ED care?

The Institute of Medicine (IOM) has concluded that differences in care exist for hospitalized patients on the basis of insurance; we attempted to determine if these differences begin in the emergency department (ED). We retrospectively studied high-acuity adult visits to one ED over 6 months, utilizing electronic databases. Uninsured patients were more often younger, male, and non-white (n = 3899 visits; 468 uninsured, 3431 insured). Fewer uninsured patients were admitted (9.8% vs. 27.2% insured; p < 0.001). Comparing patients by admission status, there was no evidence of difference for most measures, excepting radiographic studies (admitted patients: 78.3% uninsured vs. 90.5% insured, p = 0.007; treated-and-released patients: 62.3% uninsured vs. 69.4% insured, p = 0.004). In a subset of trauma patients for whom acuity could be evaluated with Injury Severity Scores (ISS), admission rates were similar. In this pilot study of high-acuity patients, there was limited evidence of differences in most measures of ED-based patient care on the basis of insurance status.