For the first time since Jimmy Carter was president, the Centers for Medicare and Medicaid Services has posted physician fee-for-service payment data to its website for public review and analysis.

While researchers and number crunchers applaud the move, some in organized medicine are issuing warnings that the data should be used with caution as it can be misleading when taken out of context.

The Medicare Provider Utilization and Payment Data: Physician and Other Supplier Public Use File was made available by CMS at the beginning of April. It includes provider names and addresses, summaries of services provided, Medicare's allowable rate and the amount it paid for those services. It is based on Medicare Part B payments made in 2012.

CMS made the file available with a caveat that there are limitations to the data — a point with which the American Medical Association agrees, which is why it has successfully advocated for more than three decades to keep it private.

The AMA argues that because the data does not reflect a physician's entire practice — it does not include claims paid by Medicare Advantage or private payers, for example — that it is not an accurate reflection of a physician's overall performance. The data is also not risk-adjusted to account for the severity of some patients' conditions, the AMA warns.

Management consultant Abhay Padgaonkar agrees there is the potential for the data to be misinterpreted. But, he doesn't buy all of the arguments about the limitations, he said.

The data shows Medicare paid out $77 billion to more than 880,000 healthcare providers in 2012, including $12 billion for about 214 million office and outpatient visits.

One issue raised by the AMA is that the amount shown as paid out to a physician may not have all gone to that physician. Residents or midlevel practitioners may have billed under that physician's National Provider Identifier (NPI), according to the AMA.

Padgaonkar doesn't understand this argument because when he ran a medical practice before becoming a consultant, there were few circumstances under which others could bill using a physician's NPI. Doing so on a regular basis "was a no-no," he said.

Additionally, Padgaonkar argues that in many cases, the amounts reported in the Medicare data might be an under-representation of what the physician actually collected. The database shows what Medicare's allowable rates are and what was paid, which is usually about 80 percent. This does not include deductibles, co-pays or co-insurance amounts paid for out-of-pocket by patients or by their supplemental policies, Padgaonkar explained.

The AMA is also concerned that patients will draw inaccurate conclusions about quality based on payments and costs.

"Thoughtful observers concluded long ago that payments or costs were not the only metric to evaluate medical care. Quality, value and outcomes are critical yardsticks for patients. The information released by CMS will not allow patients or payers to draw meaningful conclusions about the value or quality of care," said AMA President Dr. Dee Hoven, in a statement.

The AMA recently published a document, "AMA Guide to Media Reporting on CMS' Medicare Physician Claims Data" to help prevent misinterpretations of the data.

But others argue that the data goes a long way in helping consumers determine quality, especially when combined with other data sources.

The Health Data Consortium, a collaboration of government, nonprofit and private-sector organizations working to foster the availability and innovative use of healthcare data, launched a "Code-a-Paloooza Challenge" for developers to create apps that use Medicare data. The challenge is being sponsored by the HDC, the Office of the National Coordinator for Health IT and CMS. Use of other data sets is encouraged.

"The thrust of Code-a-Palooza is based around the premise that this is a complex data set that no one has had access to until now, and so there is an opportunity to transform it into something of value to consumers," said Dwayne Spradlin, CEO of the Health Data Consortium.

"Contest entrants can use parts of this data, and supplement that with other, existing data, but the goal is to allow consumers to visualize that data in a way that is understandable and actionable and gets to a real user experience."

Padgaonkar and Spradlin agree that the layperson would likely not find much value in the data file if he or she was to access it. For one, the file is too large to be imported into a simple database program such as Excel, Padgaonkar said.

But there is great value by having it in the public domain, they argue. The data may only be meaningful to analysts, data crunchers and the media initially, "but once we begin to disentangle this web we call healthcare, then we will begin to understand it better and ask more targeted questions," Spradlin said.

Padgaonkar said physicians may make better choices knowing they may become the focus of scrutiny from analysts or the media. Some of the highest-earning physicians in the country, for example, have had a spotlight placed on them since the data was made public.

Using the data, major media organizations identified many outliers, such as a Florida ophthalmologist who collected more than $21 million in 2012, and an Arizona rheumatologist who billed Medicare nearly $4.7 million and collected $1.6 million.

"Transparency is good, generally," Spradlin said. "And in this case, it's needed as a solid start to making the data more valuable and connecting it in a way that evolves into a better understanding of our healthcare system."