Insuring more Americans will help keep people out of the emergency room and thereby cut costs, some advocates of the new health law said during the debate on it. “The uninsured will get coverage, no longer left to the emergency room for medical care,” House Speaker Nancy Pelosi wrote in Roll Call in May.

But those on the ER frontlines beg to differ. Two-thirds of emergency department administrators believe that the law will increase their patient volume, while just 5 percent say patient volume will decrease, according to a new survey of more than 600 administrators conducted by the Schumacher Group, a Louisiana firm that manages 187 emergency departments across the country. Part of the problem may be the shortage of primary care physicians: 64 percent predicted their emergency department would see more patients unable to get into a doctor’s office right away.

“I would expect a lot more gridlock” in emergency departments, and “more boarding of patients” while they wait to be transferred to other hospital departments, says Kip Schumacher, chairman and CEO of the Schumacher Group. Many patients already have a difficult time getting a doctor’s appointment. As more people gain insurance under the new health law, the problem is likely to get worse. “Where you used to get an appointment in a week or so,” he says, “now you may wait four.”

Studies suggest the administrators’ concerns may be well-founded. A 2010 brief by the National Center for Health Statistics, part of the Centers for Disease Control and Prevention, found that while the uninsured were slightly more likely than the privately insured to have visited the ER in the past year, Medicaid recipients were far more likely to do so than both groups.

A study by the Robert Wood Johnson Foundation produced similar findings: after adjusting for health, income and other factors, uninsured patients used the ER at the same rate as the privately insured, while Medicaid patients used the ER at much higher rates.

Under the new law, Medicaid will be extended to all adults earning less than 133 percent of the federal poverty level, which will add 16 million more people to the program by 2019, according to the Congressional Budget Office.

There are more than 120 million ER visits each year. Administrators are understandably worried about increases. The idea that health insurance coverage will help keep people healthy and out of the emergency room “sounds great in principle,” says Schumacher, “but that’s not what happened in Massachusetts.” The state’s universal health insurance law was passed in 2006, and officials hoped improved coverage would keep people out of the ER. But emergency visits instead rose by 9 percent from 2004 to 2008.

The survey of ED administrators also found:

•  Nearly three-quarters said that a shortage of specialist physicians available to cover the ER posed at least a moderate risk to their patients.
• Seventy-three percent reported that their hospitals had invested in electronic medical records; 56 percent of those who had invested said that it was not worth the cost, but 76 percent believe it will eventually pay off.
• Seventy percent reported that they boarded mental/behavioral health patients for 24 hours or more because they were unable to transfer them to an inpatient facility. Ten percent said they had boarded mental health/behavioral patients for as long as a week or more.