Visits to emergency departments in the USA increased substantially over a ten-year period ending in 2007, reveals a report in JAMA (Journal of the American Medical Association). Between 1997 and 2007 total annual visits to EDs (emergency departments) increased 23.1%, from 94.9 million to an estimated 116.8 million – double the expected increase for this period.

American emergency departments (EDs) provide services to all individuals, regardless of their insurance cover or ability to pay – a virtually unique service in the US health care system.

The authors write:

As such, the Institute of Medicine has labeled EDs as ‘the Safety Net of the Safety Net . . . the provider of last resort for millions of patients who are uninsured or lack adequate access to care from community providers.’

Among all EDs, the Centers for Disease Control and Prevention further identified a subset as safety-net EDs because these EDs provide a disproportionate share of services to Medicaid and uninsured persons.

Previous studies have revealed that an increasing number of uninsured or underinsured Americans are using emergency departments. There is growing concern that the numbers could eventually undermine this health care safety net.

Ning Tang, M.D., University of California, San Francisco, and team examined the variations in ED visit rates in the USA to assess the hypothesis that EDs are serving a growing number of people in a safety-net role.

Information from the National Hospital Ambulatory Medical Care Survey for the period 1997-2007 was arranged by age, sex, race, ethnicity, insurance status, safety-net hospital classification, triage category, and disposition.

If over 30% of an emergency department’s total visitors was made up of individuals with Medicaid, or over 30% of total visits were by uninsured people, or if a combination of the two made up over 40% of the total, then that ED was classified as a safety-net. Visit rates were calculated using annual U.S. census estimates.

The researchers found that, for the 1997-2007 period:

  • Total emergency department visits increased from 94.9 million to 116.8 million
  • Total emergency department visits increased 23.1%
  • The increase was double what one might expect for one decade
  • Emergency department visit rates increased from 352.8 to 390.5 per 1,000 persons
  • The total number of emergency departments dropped by 5%
  • Factoring in the growth in the U.S. population, visits by the 18- to 44-year-old and 45- to 64-year-old populations accounted for the greatest increase in ED visits.
  • Emergency department visit rates among adults with Medicaid increased significantly, from 693.9 to 947.2 visits per 1,000 enrollees.
  • Adults with private insurance and Medicare showed no significant change in ED visit rates
  • Among adults with Medicaid, the ED visit rate for ambulatory care-sensitive conditions per 1,000 enrollees increased from 66.4 to 83.9.
  • Median (midpoint) ED wait times to see a physician increased from 22 minutes to 33 minutes
  • The number of facilities qualifying as safety-net EDs increased from 1,770 in the year 2000 to 2,489 in 2007

Of concern, the authors added:

One of the nation’s most severe recessions started in 2008, and with record job losses in 2008 and 2009, an estimated additional 5.8 million Americans be¬came uninsured and an estimated 5.4 million enrolled in Medicaid and SCHIP [State Children’s Health insurance Program].

Our findings suggest that increased enrollments in Medicaid between 1999 and 2007 have had substantial effects on ED volume and crowding, and that at least part of this may reflect limited access to primary care services for Medicaid enrollees. A deeper examination of the differential access to primary care by insurance type is needed to better understand health care utilization patterns by patients with Medicaid, and to develop more effective strategies for reducing pressure on the safety net.

“Trends and Characteristics of US Emergency Department Visits, 1997-2007”
Ning Tang, MD; John Stein, MD; Renee Y. Hsia, MD, MSc; Judith H. Maselli, MSPH; Ralph Gonzales, MD, MSPH

JAMA. 2010;304(6):664-670. doi:10.1001/jama.2010.1112

Written by Christian Nordqvist