The percentage of uninsured patients visiting emergency departments is apparently in sync with the general population:
Most emergency department patients have health insurance and regular primary care physicians, according to a study published on Wednesday by the American College of Emergency Physicians, the Los Angeles Times reports. For the study, researchers from the Robert Wood Johnson Foundation and the University of California-San Francisco surveyed 32,669 households in the U.S. in 2001. According to the study, respondents without health insurance accounted for about 15% of ED visits. In addition, the study finds that about 84% of respondents who visited EDs four or more times annually had health insurance and that 81% had access to primary care through a physician or a clinic. About half of respondents who visited EDs four or more times annually were enrolled in public health insurance programs such as Medicaid or Medicare, and one-third had private coverage, the study finds. The study estimates that about 45 million U.S. adults made a total of 80 million visits to EDs between July 2000 and June 2001. Some experts said that the study indicates an expansion of health insurance alone would not significantly help EDs address problems with overcrowding, which they said results in large part because patients cannot obtain appointments with their physicians or must wait for hospital beds (Yi, Los Angeles Times, 3/29).
As 15% of the population is uninsured, this makes sense. What's more interesting here is the realization that 45 million adults made 80 million visits -- which means that several patients (the majority being insured) are visiting the ED too often. I've been a patient in the ER maybe twice in my life; several of these patients are going almost twice a year (and others certainly more).
But I think most ED docs could tell you that an expansion of insurance alone would be insufficient to fix our emergency problems.