Too many Americans get care in emergency rooms instead of doctors offices — and expanded health coverage is making the problem worse rather than fixing it.

Three in four emergency room doctors said patient visits have increased since the Affordable Care Act's requirement to have health insurance went into effect, in an email survey released Monday by the American College of Emergency Physicians.

That's not the news some healthcare advocates had hoped for. The thought was that by expanding health coverage to more people, they would get their ailments treated earlier by primary care doctors and could avoid visiting emergency rooms, which already struggle with an overload of patients.

"I think a lot of people shared our hope that when you gave people access to Medicaid, they would go to the doctor, get preventive care and not need to go to the emergency department," said Katherine Baicker, a health economics professor at Harvard. "That's a reasonable hope."

Getting insurance to more people is one thing the 2010 healthcare law has accomplished. An estimated 16 million previously uninsured people are now covered, some through Medicaid and others with private plans bought via online marketplaces.

But instead of pulling back on emergency room care, the newly insured now have a plan to pay for those visits so they're not responsible for the entire bill. And that seems to be driving the change in patient load, at least for now.

"There are these two competing stories," said Baicker, who had a study published last year finding that when Oregon expanded Medicaid, the newly insured visited the emergency room more than the uninsured.

"People could go less because they can visit a primary care doctor, or they could go more because the emergency department is now more affordable," she said.

Of the survey respondents, 47 percent said their patient volume has increased slightly since Jan. 1, 2014, while 28 percent said it rose a lot.

Much of that is likely driven by low-income Americans who have become newly eligible for Medicaid in states that chose to expand it. More than half the doctors said they've seen their volume of Medicaid patients increase, although a quarter didn't know which of their patients belong to the program.

In general, Medicaid patients are more likely to visit the emergency room than patients with private insurance. The state-federal program paid for 28 percent of all emergency department visits in 2010, even though 16 percent of the population was on Medicaid.

And while the emergency room is important for just that — emergencies — there's a widely recognized need for Americans to prevent or manage chronic conditions before they get so severe that costly emergency care is needed. That requires a way to pay for regular doctor visits, usually through insurance.

President Obama emphasized the problem in 2009, when he was first pushing for a major health reform bill.

"I think it is very important that we provide coverage for all people, because if everybody's got coverage, then they're not going to the emergency room for treatment," he said at the time.

There's logic to that thought, experts say, but it's competing with several other factors. For one thing, patients who lacked health coverage until recently may be in the habit of obtaining all their healthcare from emergency departments.

"I think most health providers will be able to tell you there is a select group of super utilizers," said Orlee Panitch, an emergency physician for MEPHealth in Germantown, Md., and chairman of the Emergency Medicine Action Fund, which commissioned the survey. "They need a higher level of care of some sort."

It's easier to visit the emergency room, which is open all the time, than it is to schedule a checkup. That's especially true for Medicaid patients, as fewer physicians participate in the program due to lower reimbursement rates than what they can get from private insurance.

The problem also stems from a nationwide shortage of primary care doctors, which makes it a challenge for patients to obtain a timely doctors appointment, regardless of what kind of coverage they have.

"You have a situation where people have [an insurance] card, but they don't have access," Panitch said. "The card doesn't equal access."