There's a headline turning up in a handful of newspapers today that looks something like this in the Wall Street Journal:

Or this in USA Today:

Generally, I think the idea that Obamacare increases emergency room visits will turn out to be true. The best research we have shows that when people gain health insurance coverage, they use more medical care — emergency care included.

But we don't have the data to prove it quite yet, and it's certainly not in the study these articles cite. They rely on an American College of Emergency Physicians survey released this morning. And there were two big reasons I was cautious about the study and decided not to cover its main finding.

This study is about perception and not actual visits. ACEP asked their members whether since January 2014 they thought visits to their emergency department had increased greatly, increased a little, remained the same, or decreased. About three-quarters of respondents said visits had increased to some degree. Is this an accurate representation of whether visits have actually increased? I have no idea — but I'm skeptical of relying on doctors' memories of the past year and the whirlwind of patients they saw. If you asked me whether I wrote more or fewer stories this year than last year, I'd probably say more — the recent stories I wrote were a lot of work, and I remember them better! Am I a reliable estimator? I have no idea. We don't know how much of this change is due to Obamacare. Older data shows that year over year, emergency department visits have gone up. One federal study that relies on administrative health-care data shows visits went up 4.5 percent between 2006 and 2011. So we'd generally expect visits to increase this year, too, regardless of whether we'd passed a large insurance expansion.

The reason this study is getting so much attention at all is because of how Obamacare boosters initially sold the law, making the case that it would reduce expensive emergency room trips by increasing access to primary care services.

"Our health care system has forced too many uninsured Americans to depend on the emergency room for the care they need," Health and Human Services Secretary Kathleen Sebelius said in a July 2009 statement making the case for health reform. "We cannot wait for reform that gives all Americans the high-quality, affordable care they need and helps prevent illnesses from turning into emergencies."

The idea here was that uninsured Americans relied on the emergency room because no other doctors would see them. As they gained coverage, the thinking went, they would start going to the primary care doctor instead.

Research that has come out since suggests this is unlikely to be the case: insurance coverage reduces financial barriers to both primary care and emergency care. An important study published in 2013 showed that an insurance expansion in Oregon increased emergency room visits.

As I said earlier: I generally think the overall conclusion of these articles will prove right, and that those who hoped Obamacare would reduce emergency care will end up disappointed. But right now, there isn't the data to prove that — and you shouldn't believe the studies telling you otherwise.