More Medicaid patients going to ER, study finds

Using data from 1997 through 2007, the researchers found that ERs are increasingly serving as "safety nets" in American health care, because by law they must treat all patients regardless of insurance or their ability to pay, the researchers say.

"In 1999 adults with Medicaid visited the emergency department at a rate 3.5 times higher than the rate of adults with private insurance, and in 2007 adults with Medicaid visited the emergency department at a rate five times that of adults with private insurance," she said.

Many of these visits by Medicaid patients were for conditions that could have been managed in a primary care clinic, Tang noted.

They found that during the time period studied, annual emergency department visits went from about 94.9 million to 116.8 million, an increase of 23%, which is almost twice what was expected based on population growth, they said.

The biggest increase in ER visits was seen in people 18 to 44 years old and those 45 to 64.