This might put some of the Obamacare debate to bed. But probably not. A new survey suggests that nearly six in 10 people who bought health insurance from Obamacare exchanges in the first enrollment period were previously uninsured—many for several years or more. "There has been considerable debate about how many people signing up for coverage in the new exchanges were uninsured," Kaiser Family Foundation President Drew Altman said as he announced results of the survey.

A Sunshine Life and Health Advisors agent explains Obamacare at the Mall of the Americas in Miami on March 31, 2014. Getty Images

The survey also found that people who either had their old individual health plans canceled or voluntarily switched were as likely to pay less for their new Obamacare plans as they were to pay higher premiums.

Read MoreDr. Oz grilled over diet scams

However, 43 percent of people with Obamacare-compliant plans said they found it "very difficult" or "somewhat difficult" to pay their monthly premiums. The survey published Thursday also found that people insured by plans that now comply with Affordable Care Act standards are more likely to describe themselves as being in "fair" or "poor" health than those who remain in plans that aren't compliant with ACA rules.

While that somewhat-less-healthy overall "risk pool" may increase pressure on insurers to hike premiums in coming years, insurers had priced their first year of Obamacare premiums with the expectation that enrollees would tend to be less healthy overall than people insured under pre-ACA plans. The telephone survey polled 742 nonelderly adults who bought their own insurance plans in the individual market, as opposed to through an employer. The foundation noted that this group "has been the subject of much conjecture and political debate" in the runup to the October launch of the Obamacare exchanges, and in the six-month open enrollment period thereafter. Read More'Silver' Obamacare lining: $69 premiums

About two-thirds of this group bought plans that comply with ACA rules—which among other things mandate preventative care at no out-of-pocket charge—while one-third of the group is still in plans that are not ACA-compliant. Most of those noncompliant plans were allowed to remain in effect after initial technical problems with the Obamacare exchanges last fall made it difficult, if not impossible, for millions of people to buy coverage on those online sites. People with individual insurance plans are nearly evenly split overall in their views of Obamacare. Forty-seven percent of respondents had a favorable view of the ACA, while 43 percent have an unfavorable view, the survey found. In contrast, the overall US nonelderly adult public is more negative about Obamacare, with 46 percent viewing the law unfavorably, and 38 percent having a favorable opinion of it. The survey results come more than a month after the Obama administration boasted that 8 million people had enrolled in health coverage via individual plans sold on government-run exchanges including HealthCare.gov, and as insurers begin proposing plan rates for 2015.

While administration officials have been riding a wave of positive press about Obamacare in recent weeks, they were being excoriated last winter after reports that nearly 5 million people had had their insurance plans canceled because they were not compliant with ACA rules. Those reports lead critics to argue that the majority of enrollees on the Obamacare exchanges were merely people who needed to replace their canceled plan—not the previously uninsured, who were supposed to be the primary beneficiaries of the ACA. Obamacare proponents in response argued that plan cancellations had routinely occurred before Obamacare, but the lack of hard data on the actual number of cancellations as a result of the ACA kept the issue alive. Read MoreUS health system tops in spending, last in results

On Wednesday, heath-care researcher Jon Gabel wrote on the Health Affairs blog that "recent survey data indicates the number of persons affected by cancelled policies was about 1.9 million persons, less than the often cited 4.8 million estimate." A day later, the Kaiser survey results found that 57 percent of people who bought individual insurance on the exchanges said they had been uninsured before enrolling in coverage. And just 16 percent of enrollees have been covered by a different individual insurance plan before they purchased a new one on an exchange. Of the previously uninsured enrollees, 23 percent had not had insurance for two to five years before they bought an Obamacare plan, and 44 percent said they had not had health insurance for five or more years.