Fewer emergency rooms are serving more patients who wait longer than ever to see a doctor. This is the bleak picture painted by a study of emergency room use from 1997-2007.

One surprising finding from the study is that the rise is due to increased use by Medicaid patients, not the uninsured.

Previous studies and popular observation have suggested that more people than ever are visiting hospital emergency rooms. Emergency rooms have become the provider of last resort for millions of uninsured or underinsured patients, as well as for patients who lack adequate access to doctors at other locations in their community.

ER visits increased by 23% over that 10 year period, an increase twice as large as what would be expected from national population growth. And the average wait to see a doctor rose by 50%, from 22 minutes to 33 minutes.

Researchers from the University of California, San Francisco set out to see if patient visit data supported these claims.

They analyzed emergency room visit data collected by the National Hospital Ambulatory Medical Care Survey between 1997 and 2007.

The data showed that ER visits increased by 23% over that 10 year period, an increase twice as large as what would be expected from national population growth. And the average wait to see a doctor rose by 50%, from 22 minutes to 33 minutes. Total annual ER visits increased from 94.9 million in 1997 to 116.8 million in 2007. But the total number of ERs available to the public declined by 5% during these 10 years.

Visit rates by patients with private insurance, Medicare and by the uninsured showed no significant change. But the visit rate by Medicaid patients increased by over 36% between 1999 and 2007, rising from 693.9 visits per 1000 enrollees to 947.2.

The researchers suggest that one reason for the rise in ER visits is the inability of Medicaid patients to obtain health care elsewhere. Patients don't want to visit the ER; they go because they don't know where else they can be treated.

Hospital Emergency Departments serve a unique role in U.S. health care because they provide care to all patients regardless of their insurance coverage or ability to pay. As such, they serve an increasing number of people as a medical safety net. But some ERs, particularly those in poorer areas or densely populated sections of large cities, serve a greater proportion of safety net patients than others. The researchers defined an emergency department as a safety net facility if 30% or more of its patients were on Medicaid, 30% or more of its patients were uninsured or if Medicaid and uninsured patients combined formed 40% or more of its total patients.

The number of these safety net facilities rose from 1,770 in 2000 to 2,489 in 2007. This suggests that many emergency rooms are now treating a type of patient they didn't see in the past. Emergency departments were once designed to treat serious medical emergencies but are now being used by many patients as primary care providers. To a patient unable to find treatment elsewhere, almost any medical condition can quickly become a medical emergency.

The authors note that the study data only extends through 2007. In 2008, a severe recession began in the U.S. and an estimated 5.8 million Americans have since lost their health insurance. An additional 5.4 million Americans have either enrolled in Medicaid or SCHIP (State Children's Health Insurance Program) since the start of the recession. This is likely to further increase the burden on emergency rooms.

The study was designed to investigate patterns of ER usage, not to suggest solutions to the many problems causing these patterns and caused by them. The authors do point out that there's a definite need to develop effective strategies to reduce the pressure being put on patients who need to use ERs and on the ERs themselves.

An article on the study appears in the August 11, 2010 issue of the Journal of the American Medical Association (JAMA).