About 14 million Americans have gained health coverage since Obamacare's insurance expansion began in 2014 — but those new enrollees haven't swamped the nation's doctors' offices, new research shows.

When the health-care law started, there was concern that an influx of new patients could overwhelm doctors. It's already hard enough to get an appointment with a primary care provider — wouldn't millions of newly insured Americans just exacerbate the problem?

New data from 16,000 providers across the country, pulled by the medical records firm AthenaHealth, shows that requests for new appointments just barely edged upward in 2014. The proportion of new patient visits to primary care doctors increased from 22.6 percent in 2013 to 22.9 percent in 2014.





Researchers know people do tend to go to the doctor more when they have insurance. That point, proved most famously in the RAND Health Insurance Experiment of the 1970s, is pretty much undisputed.

14 million obamacare sign-ups is, in some ways, a drop in the bucket

And Obamacare has helped millions of Americans gain insurance coverage. Federal data released earlier this month shows that the uninsured rate has fallen 35 percent since the coverage expansion began in 2014. Obamacare has expanded medical insurance faster than any new policy since Medicare and Medicaid were created in 1965.

In that way, the health law's insurance expansion was big. But put another way, it's also small: 14 million people gaining coverage in a country of more than 300 million residents is kind of a drop in the bucket. We're talking about 4 percent of the country going from uninsured to covered.

Another Obamacare concern a few years ago was that these newly insured patients, who may have gone without care for years, may have more complex medical conditions that had gone unmanaged.

obamacare enrollees aren't sicker

The AthenaHealth data suggests, somewhat surprisingly, that this isn't the case: doctors didn't start seeing sicker patients after the insurance expansion started.

"We found no evidence that patient complexity increased in 2014," the report finds. "Physician work intensity per visit remained flat, diagnoses per visit increased slightly, and the percentage of visits with high-complexity evaluation and management codes actually decreased slightly."

This is what happened under Romneycare — and, five decades ago, with Medicare

One reason the Obamacare news isn't a surprise: it looks similar to what's happened with previous insurance expansion. Since Massachusetts expanded coverage in 2006, annual surveys by the Massachusetts Medical Society haven't shown any clear pattern in changes to care access.

There was definitely been a big drop in primary care doctors accepting patients, from 66 percent in 2005 to 45 percent in 2013. The wait time to see an internist has bounced around a lot — 47 days in 2005, 44 days in 2012, and then up to 50 in 2013 — showing no clear pattern related to the state's insurance expansion.

And if you go even further back in history, you see the same thing happened with Medicare. Back then, there was a lot of worry that an influx of newly insured seniors would swamp the American health-care system.

When I worked at the Washington Post, I looked through newspaper archives for coverage of the Medicare launch to get a sense of expectations. Questions like these — raised by a New York Times writer in April 1966, a few months before Medicare launched — were pretty typical:

What will happen then, on that summer day when the federally insured system of paying hospital bills becomes reality. Will there be lines of old folks at hospital doors, with no rooms to put them in, too few doctors and nurses and technicians to care for them?"

But when Medicare launched on July 1, 1966, it went pretty smoothly — the long lines didn't materialize. This is what the Washington Post wrote about the program's launch:

It was a smooth transfusion, undramatic as a bed change. At 12:01 a.m. yesterday, Uncle Sam began paying the bills of close to 1,000 patients over 65 in area hospitals. The transition to Medicare, the federally financed health plan, was as uneventful as it was historic. The influx of card-carrying Medicare patients was a trickle, not the storm that had been predicted by some.

What all these programs have in common: they are big ideas that fundamentally change the health insurance system in the United States. The Affordable Care Act opened the insurance market to everybody; Medicare guaranteed coverage to Americans over 65.

But in practice, these programs are relatively small: each only insured a small chunk of the population. Even though they're remaking American health care, they're doing so in a small, slow progression. That helps explain why none of these coverage expansions have overwhelmed doctors, despite our expectations.

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