Study finds 83% of ED patients have insurance

EDs unfairly penalized by upper management

Common wisdom may say that the nation’s EDs are being filled up with the uninsured, but a new study on EDs asserts that more than 80% of patients seen in EDs have health insurance and a usual source of health care such as a primary care physician.

The study, which has been published on-line by the Annals of Emergency Medicine, found that 83% of ED visits were made by people who had a doctor, a clinic, or who were members of a health maintenance organization. In addition, 85% had medical insurance, and 79% had incomes above the poverty level.1

"I think our major finding is that the individuals who come to our EDs are mainstream Americans who have doctors and have insurance," asserts Ellen J. Weber, MD, a professor in the division of emergency medicine at the University of California, San Francisco, who led the study. Interestingly, the annual National Hospital Ambulatory Medical Care Survey (NHAMCS) conducted by the Centers for Disease Control and Preven-tion shows similar statistics: About 17% of ED patients are not insured.2 (For information on NHAMCS, see resources below.)

That statistic has significant implications for ED managers, and in fact, that possibility was one of the reasons Weber undertook the study.

"We thought that policies that affected EDs were somewhat impacted by what we believed were misperceptions of who visits EDs — i.e., the uninsured, the fringes of society," she says. "And as a result, the EDs were not getting the staff or the funding they needed because they were not seen as places where mainstream Americans went," she explains.

The data on which Weber based many of her findings was not an ED study, but rather a household survey conducted by the Washington, DC-based Center for Studying Health System Change.3 "It looked at the use of health care — health status, age, insurance — and then what health care resources they used [i.e., EDs]," she adds.

"That allowed us to decide whether someone who had certain characteristics was more or less likely to use the ED." Another major source of the study, Weber says, was NHAMCS.

She asserts that these findings should have an impact on the way upper management views EDs — specifically, the amount of funding they receive.

"Upper management needs to recognize that ED managers and their staffs need the same level of attention that people in other parts of the hospital are getting — especially with the overcrowding and worry about transfers [we are facing]" she insists. "But, for example, elective surgeries are prioritized over emergency patients because [the ED] is thought not to be there for the hospital’s bottom line."

That thought is wrong, Weber says. "The patients who go to the ED are sicker, probably have a very legitimate reason to be there, and should have at least equal priority for the beds," she says. "They are not a drain on the financial system of the hospital."

The study’s findings, Weber argues, could be used to affect how ED managers argue for their budget, or compete for who gets the next bed. "They can argue, Our patients are also part of our mainstream system — they are not just people who came out of the park, and if they do not get equivalent priority, they will go somewhere else, and we’ll lose them in the tertiary care system,’" she suggests.

You might think that ED physicians in border states such as Texas, where illegal immigrants make up a significant portion of the population, would perceive a different reality than the one portrayed in Weber’s study — and you’d be right.

However, Claudie Jimenez, MD, associate professor of surgery at the University of Texas Southwestern Medical Center at Dallas, does not reject Weber’s findings outright. "While the numbers of the uninsured do continue to rise, the problem of ED overcrowding is much more complex, and this article speaks to this issue," she says.

Jimenez works in a large urban county ED. "While the majority of our patients are uninsured, many patients who have coverage still come to the ED for care," she explains.

In a study the facility conducted in 2001, 63% of patients without insurance said they preferred to use the ED as the primary source of care, and 40% of patients with private insurance also preferred to use the ED.

This survey was conducted among patients who presented to the ED with congestive heart failure, diabetes, or hypertension, Jimenez says. These are chronic conditions that require routine maintenance care, she notes.

"These patients may have exacerbations of their disease that requires emergent intervention and may not be able to be managed in an ordinary primary care office, or their condition necessitates an admission to the hospital," Jimenez says. "Only 29% of our surveyed population called for an appointment with a primary care physician before presenting to the ED for care."

While it is believed by some that a large undocumented immigrant population is putting a significant strain on health care services, especially in border states, actual numbers are very hard to come by, Jimenez adds.

"While the lack on health care coverage is an important issue that needs to be addressed, ED overcrowding is more likely the direct result of a severe shortage of inpatient beds for an aging patient population with chronic conditions," she concludes.


1. Weber EJ, Showstack JA, Hunt KA, et al. Does lack of a usual source of care or health insurance increase the likelihood of an emergency department visit? Results of a national population-based study. Ann Emerg Med 2005. (This article has been published on-line and is available for download free at: Click on "Annals of EM" on the right side of the page. Next, on the left side of the page, click on Mosby’s web site. At press time, it was scheduled to be published in the January 2005 edition of Annals of Emergency Medicine.)

2. McCaig LF, Burt CW. National Hospital Ambulatory Medical Care Survey: 2002 Emergency Department Summary. Washington, DC: DHHS Publication No. (PHS) 2004-1250, No. 340; 2004.

3. Strouse R, Carlson B, Hall J. Center for Studying Health System Change: Household Survey Methodology Report 2000-01 Round Three, Washington, DC: Center for Studying Health System Change; 2003. (This study can be downloaded free at


For more information on the impact of the uninsured on EDs, contact:

  • Claudie Jimenez, MD, Associate Professor of Surgery, University of Texas Southwestern Medical Center at Dallas. Phone: (214) 648-8593. E-mail:
  • Ellen J.Weber, MD, Professor, Emergency Medicine, University of California, San Francisco. Phone: (415) 353 1238. E-mail:

For more ED-specific information in the National Ambulatory Medical Care Survey, go to Under "Data Highlights — Selected Tables, Charts, and Graphics," click on "Emergency Department Visit Data.