Jordan Rau of Kaiser Health News is carving quite a reputation for himself on the hospital beat, and helping to educate the public and the press while he’s at it. Last week Rau did a bangup job covering a study that presents a cautionary tale. The study, published in Medical Care Research and Review, pokes a pretty large hole in the “idea that uneven Medicare health care spending around the country is due to wasteful practices and overtreatment—a concept that influenced the federal health law,” Rau reported.

What he’s talking about is the much-publicized work of the Dartmouth Institute for Health Policy & Clinical Practice, whose famous Dartmouth Atlas has been consulted by journos and policymakers for years. Reporters have considered Atlas data their holy grail, and stories showing wide regional variation in medical spending have become staples.

The gist of the Dartmouth research is that aggressive physicians who do more procedures and tests do so in part because they can make more money that way, and this accounts for some of the unexplained regional differences in spending.

Beltway policymakers during the 2008 election—along with a high-profile 2009 New Yorker piece by Atul Gawande that showed high spending in McAllen, TX—popularized the theory, and sparked Obamacare reforms that financially penalize hospitals that generate high costs for the system with such practices as readmitting too many patients after an inpatient stay.

Health policy experts have had divided opinions about the Dartmouth data, but this latest pushback, Rau says, is “one of the sharpest attacks yet.”

When the study’s researchers examined the diagnoses for Medicare beneficiaries that were reflected in the claims file for Medicare payments, they concluded that patients in some parts of the country were simply sicker than those in other parts—and that is what accounts for much of the higher spending in some regions. Speaking about the Dartmouth researchers, James Reschovsky, the study’s lead author, told Rau:

They were trying to spin a simple story from a world which is far more complex and far more nuanced. They are to be credited for highlighting that there’s a lot of inefficiency in the delivery of health care in the United States. They defaulted by hanging their hat on geographic determinants of efficiency, and I think that premise is fundamentally being torn down.

When Rau questioned Dartmouth economist Jonathan Skinner, Skinner pushed back against the pushback. He replied in an email that the study critical of the Atlas was “fatally flawed,” and that Dartmouth researchers could not replicate it. Rau also rang up Maribeth Shannon, a senior official at the California Healthcare Foundation, one of the funders of the Atlas, who seemed to critique people who have written about the Atlas. “People are stretching the research beyond the reasonable bounds. We always have to take the research with its limitations.” In other words, she seemed to be fingering the press for running with conclusions that might not be so conclusive after all.

This War of the Researchers does raise questions of whether journalists who have waded into these waters have been swamped by the Dartmouth tide. Have we been skeptical enough? Have we asked the right questions? It’s hard to say who’s right and who’s wrong in these matters.

Still, Rau’s story should give reporters plenty to think about before doing their next regional comparison story. Paul Levy, former CEO of Beth Israel Deaconess Medical Center in Boston, and who writes a popular blog called “Not Running a Hospital,” tweeted the other day: “Jordan Rau publishes a provocative story. Will it suffer from political correctness?”

It has been politically correct in healthcare journalism to quote and use The Dartmouth Atlas. This study indicates that maybe we should ask more questions about it, as we always should when new research surfaces. A good place to start when more data surfaces about any health policy is a list called “Top 10 Questions for health policy journalists” on the website run by British health journalist and professor named John Lister. Lister’s questions are adapted from a similar list for covering medical studies created by Gary Schwitzer at HealthNewsReview.org.

Trudy Lieberman is a fellow at the Center for Advancing Health and a longtime contributing editor to the Columbia Journalism Review. She is the lead writer for The Second Opinion, CJR’s healthcare desk, which is part of our United States Project on the coverage of politics and policy. Follow her on Twitter @Trudy_Lieberman.